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Protein

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News & Research:

• Ubiquitous nutrients suppress appetite and promote movement - Science Daily, 4/20/22 - "Of the 21 amino acids our bodies require, there are 9 they are unable to produce on their own. They are called essential amino acids. Because we must obtain these through our diet, they have far been the focus of nutrition research. The other 12 amino acids are considered non-​essential. The body can produce them itself by altering other molecules ... The researchers first fed mice either a mixture of various non-​essential amino acids or a sugar solution with the same amount of calories (control group). Both groups of mice were then allowed to drink a milkshake, which they normally love. While the control group drank copious amounts of it, the mice that had been fed non-​essential amino acids avoided theirs. Instead, they went around their enclosure in search of alternative sustenance"
• Eating protein from a greater variety of sources may lower risk of high blood pressure - Science Daily, 3/10/22 - "Participants were given a protein "variety score" based on the number of different sources of protein eaten out of 8 reported: whole grains, refined grains, processed red meat, unprocessed red meat, poultry, fish, egg and legumes. One point was given for each source of protein, with a maximum variety score of 8. The researchers then evaluated the association for new onset hypertension in relation to the protein variety score ... Compared to participants with the lowest variety score for protein intake (less than 2), those with the highest variety score (4 or higher) had a 66% lower risk of developing high blood pressure."
• A diet of essential amino acids could keep dementia at bay - Science Daily, 10/22/21 - "a low protein diet can accelerate brain degeneration in mouse models of Alzheimer's disease. More importantly, they found that Amino LP7 -- a supplement containing seven specific amino acids -- can slow down brain degeneration and dementia development in these animals ... Amino LP7, indicating that the combination of seven specific amino acids could inhibit brain damage" - Note: LP7's ingredients:
  • Neurodegenerative processes accelerated by protein malnutrition and decelerated by essential amino acids in a tauopathy mouse model - Science Advances, 22 Oct 21
• High-protein Diet More Effectively Reduces Hepatic Fat Than Low-protein Diet Despite Lower Autophagy and FGF21 Levels - Medscape, 1/14/21 - "19 participants with morbid obesity undergoing bariatric surgery were randomized into two hypocaloric (1500–1600 kcal/day) diet groups, a low protein (10E% protein) and a high protein (30E% protein), for three weeks prior to surgery ... HP diet more effectively reduces hepatic fat than LP diet despite of lower autophagy and FGF21. Our data suggest that liver fat reduction upon HP diets result primarily from suppression of fat uptake and lipid biosynthesis" - See whey protein at Amazon.com.
• Higher Protein Intake Linked to Lower Risk of AF - Medscape, 4/3/20 - "the average American eats an estimated 3600 calories/day — 50% from carbohydrates, 35% from fat, and only 15% from protein ... This translates to 540 calories per day from protein, which is 135 g (since 1 g of protein has 4 calories), "which is more than enough protein for the average person ... There does appear to be a 'sweet spot' with regard to protein intake, at around 58 to 74 grams per day, along with a 'ceiling effect' above 74 grams per day, where more protein intake is no longer beneficial ... most people would be far healthier and leaner by reducing their total caloric intake from carbohydrates and fats while eating a proportionally higher protein diet closer to 25% of their total calories."" - Not sure if that quote makes sense.  The average is 135 but best is 58 to 74 so we need to increase it? - See whey protein at Amazon.com.
• A more balanced protein intake can reduce age-related muscle loss - Science Daily, 3/16/20 - "old people, compared to young and middle-aged individuals, people were more likely to eat a lower-quality protein source, such as bread, at lunchtime ... We know that older people show a blunted response to muscle building when consuming a certain amount of protein. Therefore, older individuals need to eat more protein to get the same muscle building response as younger and middle-aged people"
• High-Protein Diet Is Bad for Kidney Health - Medscape, 2/19/20 - "Given these and other data, it is time to unleash the taboo and make it loud and clear that a high-protein diet is not as safe as claimed, as it may compromise kidney health and result in a more rapid kidney function decline in individuals or populations at high risk of CKD. While more studies are needed to shed greater light, and while we expect that discussion will continue on this and other taboo topics,[17] it is prudent to avoid recommending high-protein intake for weight loss in obese or diabetic patients or those with prior cardiovascular events or a solitary kidney if kidney health cannot be adequately protected."
• High-Protein Diet Could Be Harmful, Even for Healthy Kidneys - Medscape, 11/27/19 - "Despite the fact that our patients received state-of-the-art drug treatment, we observed a beneficial effect of a low-protein intake on kidney function ... Among the four quartiles of daily protein intake, the prevalence of renal hyperfiltration (defined as an eGFR with residuals > 95th percentile after adjustment for confounders) was significantly higher among those in the highest quartile of protein intake, at 6%, compared with 5.2% among those in the lowest protein intake quartile ... those in the highest quartile of protein intake had a 32% greater risk of experiencing a rapid decline of eGFR per year compared with those in the lowest quartile"
• More protein and fewer calories help older people lose weight safely - Science Daily, 2/14/19 - "two groups: a six-month low-calorie meal plan that included more than 1 gram of protein per kilogram of body weight, plus adequate calcium and vitamin D; or a weight stability group targeting .8 grams of protein per kilogram of body weight, which is the current, government-recommended dietary allowance ... Participants lost about 18 pounds, most of it fat (87 percent), and preserved muscle mass. The control group lost about half a pound ... Even when participants lost weight, they maintained bone mass. In fact, trabecular bone score, a measure of bone quality that predicts fracture risk, seemed to improve ... Fat was lost in the stomach, hips, thighs and rear, which is important for preventing or controlling cardiometabolic diseases such as diabetes and stroke ... Participants' score on the Healthy Aging Index, which measures biomarkers that predict mortality and longevity, improved by 0.75 points" -  See protein powder at Amazon.com.
• High protein diet associated with small increased heart failure risk in middle-aged men - AHA, 5/29/18 - "Researchers studied 2,441 men, age 42 to 60, at the study’s start and followed them for an average 22 years. Overall, researchers found 334 cases of heart failure were diagnosed during the study and 70 percent of the protein consumed was from animal sources and 27.7 percent from plant sources. Higher intake of protein from most dietary sources, was associated with slightly higher risk. Only proteins from fish and eggs were not associated with heart failure risk in this study, researchers said."
• Magnesium: The Multi-Purpose Mineral - Think Muscle Newsletter - "It is important to note that increasing dietary protein intake may increase magnesium requirements because high protein intake may decrease magnesium retention"
• To manage weight, it may matter when protein supplements are consumed - Science Daily, 5/23/18 - "while protein supplementation effectively increased lean mass for all groups, consuming protein supplements with meals helped maintain their body weight while decreasing their fat mass. In contrast, consuming protein supplements between meals promoted weight gain ... The timing likely makes a difference because a person may tend to adjust their calories at a meal time to include the protein supplement." - Note: They may be right about the reason or it might just be going back to basics like in the book “Diet for a Small Planet” which claims that you have to get all eight of the essential amino acids in the right proportions at the same time.
• The many reasons you need iron in your diet - Washington Post, 10/17/17 - "Iron equals energy. Iron’s main job is to help carry oxygen from the lungs to every cell in the body. When you do not get enough oxygen to your cells, you are left feeling exhausted and weak — sound familiar, boys? Low iron is the most common nutrient deficiency in the United States. Even if my guys are not actually iron deficient, giving their cells a little more oxygen certainly cannot hurt ... Kids and adults who drink caffeine may be depleting their bodies of iron. Caffeine inhibits iron absorption, making it hard for the essential mineral to get to our cells to work its magic. Digestive distress can also inhibit the absorption of iron. Excess exercise can damage red blood cells, the cells that carry the oxygen throughout our bodies, so the body may need even more iron when exercising to the extreme. Boys, I am quite sure your twice-a-day football practices in August and September heat qualified as extreme" - See iron supplements at Amazon.com.
• Eating protein three times a day could make our seniors stronger - Science Daily, 8/30/17 - "We observed that participants of both sexes who consumed protein in a balanced way during the day had more muscle strength than those who consumed more during the evening meal and less at breakfast. However, the distribution of protein throughout the day was not associated with their mobility ... All body tissues, including the muscles, are composed of proteins, which consist of amino acids. If the protein intake decreases, the synthesis is not done correctly and this leads to a loss of muscle mass ... "Our research is based on scientific evidence demonstrating that older people need to consume more protein per meal because they need a greater boost of amino acids for protein synthesis," says Dr. Chevalier, adding that one of the essential amino acids known for protein renewal is leucine" - See BulkSupplements Pure L-Leucine Powder (1 Kilogram).
• Recommended daily protein intake too low for the elderly - Science Daily, 5/23/17 - "The RDA you will find on the nutrition labels on your food, however, were set in 1968, and the ones used by researchers and professionals were set in 2003. A recent review published in Frontiers in Nutrition points out that both these values do not do justice to the protein needs of the elderly and critically ill ... A big disservice is being done. The prescribed 0.8 g/kg/day just isn't enough protein for the elderly and people with a clinical condition .... he points out that the quality of proteins should be considered when setting the RDA guidelines and recommending protein supplements. He argues that there should be a stronger focus on leucine; an indispensable amino acid and building block for proteins. The elderly have a higher need for leucine to build muscle proteins, and milk-based proteins (e.g. milk and whey) are a good source for this" - See BulkSupplements Pure L-Leucine Powder (1 Kilogram).
• Dietary Protein Intake and Stroke Risk in a General Japanese Population: The Hisayama Study - Stroke. 2017 May 9 - "the risks of total stroke and ischemic stroke significantly decreased by 40% (95% confidence interval, 12%-59%) and 40% (5%-62%), respectively, in subjects with the highest quartile of vegetable protein intake compared with those with the lowest one. In contrast, subjects with the highest quartile of animal protein intake had a 53% (4%-77%) lower risk of intracerebral hemorrhage"
• Remission of Pre-Diabetes to Normal Glucose Tolerance in Obese Adults With High Protein Versus High Carbohydrate Diet - Medscape, 1/14/17 - "After 6 months on the HP diet, 100% of the subjects had remission of their pre-diabetes to normal glucose tolerance, whereas only 33.3% of subjects on the HC diet had remission of their pre-diabetes. The HP diet group exhibited significant improvement in (1) insulin sensitivity (p=0.001), (2) cardiovascular risk factors (p=0.04), (3) inflammatory cytokines (p=0.001), (4) oxidative stress (p=0.001), (5) increased percent lean body mass (p=0.001) compared with the HC diet at 6 months"
• High-Protein Diet May Reduce Liver Fat in Patients With NAFLD - Medscape, 11/16/16 - "High-protein diets (30% energy from protein, 40% from carbohydrates, 30% from fats) with a favorable fatty acid composition potently reduced liver fat content in patients with type 2 diabetes and fatty liver independently of protein origin or body weight changes ... Eighteen patients ate animal protein (AP) and 19 consumed plant protein (PP) ... Intrahepatic lipids (IHL) were reduced by 48% in the AP group and 35.7% in the PP group after six weeks, both statistically significant decreases. Nine patients (three from the AP group, six from the PP group) had IHL levels below 5.56%, meaning they no longer had NAFLD"
• Do you need to eat more protein? - CNN, 10/4/16 - "While studies are mixed about whether consuming more protein leads to weight loss, research is pretty clear that protein can help you retain more of your lean muscle as you lose fat. One 2011 study suggests amping up protein to as much as 1.8 to 2 grams per kilogram (roughly 0.8 to 0.9 grams per pound) of body weight per day to stave off muscle loss when restricting calories ... Eating more protein as you get older may help you maintain muscle and ward off osteoporosis, "so you can stay stronger and more functional," says Rodriguez. In a 2015 study, adults over the age of 50 who roughly doubled the RDA (eating 1.5 grams of protein per kilogram, or 0.68 grams per pound, of body weight) were better able to rebuild and retain muscle after only four days, compared with control groups eating the RDA ... Eating more protein as you get older may help you maintain muscle and ward off osteoporosis, "so you can stay stronger and more functional," says Rodriguez. In a 2015 study, adults over the age of 50 who roughly doubled the RDA (eating 1.5 grams of protein per kilogram, or 0.68 grams per pound, of body weight) were better able to rebuild and retain muscle after only four days, compared with control groups eating the RDA"
• High protein foods boost cardiovascular health, as much as quitting smoking or getting exercise - Science Daily, 8/27/15 - "those who consumed the highest amounts of amino acids had lower measures of blood pressure and arterial stiffness ... But they found that the food source was important -- with a higher intake of amino acids from plant-based sources associated with lower blood pressure, and a higher intake from animal sources associated with lower levels of arterial stiffness ... Increasing intake from protein-rich foods such as meat, fish, dairy produce, beans, lentils, broccoli and spinach could be an important and readily achievable way to reduce people's risk of cardiovascular disease"
• Current dietary protein recommendations need updating, experts say: New research techniques help to uncover the best ways to consume dietary protein to optimize health outcomes - Science Daily, 7/22/15 - "Protein helps people stay full longer, preserve muscle mass, and when combined with adequate physical activity, has the potential to serve as a key nutrient for important health outcomes and benefits ... including a moderate amount of high-quality protein at each meal may offer an effective strategy for optimising muscle protein synthesis and potentially protecting muscle mass ... Protein continues to be the right choice for weight loss management"
• Choice of protein- and carbohydrate-rich foods may have big effects on long-term weight gain - Science Daily, 4/9/15 - "diets with a high glycemic load (GL) from eating refined grains, starches, and sugars were associated with more weight gain ... Increasing intakes of red meat and processed meat were most strongly associated with weight gain ... Increasing intakes of yogurt, seafood, skinless chicken, and nuts were most strongly associated with weight loss -- the more people ate, the less weight they gained ... Increasing other dairy products, including full-fat cheese, whole milk, and low-fat milk, did not significantly relate to either weight gain or weight loss ... The fat content of dairy products did not seem to be important for weight gain ... when people consumed more low-fat dairy products, they actually increased their consumption of carbs, which may promote weight gain"
• Older adults: Double your protein to build more muscle - Science Daily, 1/30/15 - "Current US recommendations for daily dietary protein intake are 0.8 grams/kilogram of body weight (roughly 62 g of protein per day for a 170-pound person). Previous research has shown that older adults need a protein intake of at least 0.40 g/kg of body weight at each meal (roughly 31 g of protein per meal or 93 g per day for a 170-pound person) to encourage maximum protein synthesis. This represents a significantly higher amount of protein than the recommended dietary allowance (RDA) suggests ... The research team studied 20 healthy adults between 52-75 years of age, randomly assigning them to one of four groups over a four-day test period ... while the distribution of protein across meals did not make a significant impact, total amount of protein consumed"
• High protein diets lead to lower blood pressure, study finds - Science Daily, 9/11/14 - "high blood pressure (HBP) ... participants consuming the highest amount of protein (an average of 100 g protein/day) had a 40 percent lower risk of having high blood pressure compared to the lowest intake level ... The researchers analyzed protein intakes of healthy participants from the Framingham Offspring Study and followed them for development of high blood pressure over an 11-year period. They found that adults who consumed more protein, whether from animal or plant sources, had statistically significantly lower systolic blood pressure and diastolic blood pressure levels after four years of follow-up ... When the diet also was characterized by higher intakes of fiber, higher protein intakes led to 40-60 percent reductions in risk of HBP"
• Protein has the effect of lowering blood pressure, which may play a role in reducing stroke risk - Science Daily, 6/11/14 - "the participants with the highest amount of protein in their diets were 20 percent less likely to develop a stroke than those with the lowest amount of protein in their diets ... For every additional 20 grams per day of protein that people ate, their risk of stroke decreased by 26 percent ... Protein has the effect of lowering blood pressure, which may play a role in reducing stroke risk"
• High Protein Intake Linked to Higher Type 2 Diabetes Incidence - Medscape, 4/17/14 - "The current analysis included 10,901 incident type 2 diabetes cases and a subcohort of 15,352 participants, including 736 diabetes cases, with a mean follow-up of 12 years ... used food frequency questionnaires to determine participants' eating habits ... overall, high total protein intake was associated with a 13% higher incidence of diabetes for every 10-g increment ... protein of animal origin is largely responsible for the association — not plant protein"
• Deli Dilemma: Meat and Cheese Linked to Earlier Death - ABC News, 3/4/14 - "The study of more than 6,000 American adults found those between the ages of 50 and 65 with diets high in animal protein were 74 percent more likely to meet an untimely end than those who consumed less animal protein or got their protein from non-animal sources ... For deaths due to cancer, the risk was four times higher ... Why did the effect disappear with older people? As we age, our demand for protein increases. So getting more of it from a host of sources after 65 is important in extending our longevity ... The patients whose diets were packed with protein were more than 25 percent less likely to meet an early death ... What we know for sure is older people have a problem getting enough protein ... The condition is known as sarcopenia, and is estimated to affect nearly half of seniors by the time they reach eighty years of age" - [Fox video segment on this which gets into the percentages of protein] [Science Daily]
• High-Protein Diets, Like the Popular Dr. Dukan Diet, Increase the Risk of Developing Kidney Disease in Rats, Study Suggests - Science Daily, 1/21/14 - "researchers studied 20 Wistar rats, divided into two groups of 10. The first group were fed a high-protein diet of commercial hydrolysed protein supplements with a 45% protein level. The control group were fed a normal protein diet. The experiment lasted 12 weeks, which is the equivalent of 9 years in human terms ... the rats on a high-protein diet lost up to 10% of their body weight over the 12 weeks with no improvement in their plasma lipid profile. Moreover, urinary citrate in these rats was 88% lower and urinary pH was 15% more acidic. In the animals fed a high-protein diet, kidney weight increased by 22%, glomerular area -- the network of capillaries that filter blood in the kidneys -- by 13%, and the mesangium -- a collagen structure surrounded by these capillaries -- by 32% ... Eating large amounts of fruit and vegetables reduces the risk of kidney stones forming -- probably due to their high potassium and magnesium content, which compensates for the acidity of the high-protein diet"
• Doubling the daily allowance of protein intake with diet and exercise protects muscle loss - Science Daily, 8/29/13 - "consuming twice the recommended daily allowance (RDA) of protein while adhering to a diet and exercise plan prevents the loss of muscle mass and promotes fat loss. Tripling the RDA of protein, however, failed to provide additional benefits ... assigned young men and women controlled diets for 31 days that provided dietary protein at three different levels: 1) the U.S. RDA, 2) twice the U.S. RDA, and 3) three times the U.S. RDA. Volunteers were given adequate total calories to maintain constant body weight for the first 10 days to allow their metabolism to adapt to the dietary protein level, and then for the following three weeks, weight loss was induced by restricting the total calories and increasing daily exercise sufficiently to elicit an average two-pound weight loss per week" - Click here for the protein RDA table.  I would think that most American's already get twice the RDA.  My recommendation would be to add a scoop of leucine powder twice per day.  It's got to be one of the worst tasting substances on earth though.  I put a scoop in a small jar with a lid and about a half cup of water and shack it then down it.  Then add another half cup of water and shake it again to get any remaining and down it again.  See my leucine page.
• How Much Protein Is Too Much? - cbslocal.com, 7/4/13 - "The CDC recommends women need about 46 grams of protein per day. You’ll get that much by eating a three ounce hamburger, one hard-boiled egg, eight ounces of milk and one six ounce container of Greek yogurt ... So, how much is too much? ... A good general kind of rule of thumb is try not to exceed more than one gram of protein per pound of body weight ... In the most severe cases, too much protein can actually cause kidney damage, and possibly dehydration"
• Beef up: Middle-aged men may need more to maintain muscle mass - Science Daily, 2/4/13 - "Canada's Food Guide now suggests that consuming about 3oz (0.80 g/kg/d) of meat per serving is adequate to provide protein at the recommended level ... However, our work shows that the quantity of beef needed to maximize the renewal of new muscle proteins was at least 6oz in middle-aged men. Our findings have clear ramifications for the current recommendations regarding protein to prevent muscle loss in aging"
• Eggs at Breakfast May Delay Hunger - WebMD, 5/11/12 - "researchers tracked 20 overweight or obese people, giving them either a breakfast containing eggs or cold cereal for one week. Although the breakfasts offered different protein foods, the meals themselves were equally matched in terms of calories, carbohydrates, protein, and fat ... people who had eggs in the morning felt fuller before lunch, and they also ate less food from the buffet compared to those who had cereal. Egg eaters also had lower levels of ghrelin and higher amounts of PYY3-36 during the three hours between breakfast and lunch. This suggests they felt less hungry and more satisfied between meals ... Long-term weight loss trials to compare the manipulation of protein quality without increasing protein quantity should be explored" - Note:  I fully agree.  I just seems very easy to keep my weight in check when I have eggs for breakfast.
• Quality Protein Intake Inversely Related With Abdominal Fat - Medscape, 4/11/12 - "central abdominal fat (CAF) ... The data from this study demonstrates that both quality and distribution of dietary protein throughout the day is important. The quality and distribution of protein are of particular interest to those who are energy restricted, who might benefit from the consumption of a higher quality protein source (e.g. milk, egg, beef), resulting in a higher EAA content per gram of protein. Neither carbohydrate nor dietary fat intake was associated with percent CAF, which confirms previous data, highlighting the importance of protein intake ... a plateauing of muscle contractile protein synthesis following approximately 9-10 g of EAA; meaning dietary intake of EAAs above this threshold does not significantly contribute to the accretion of skeletal muscle" - See my yogurt recipe at the top of my yogurt page.
• Watching Your Protein May Be Key to Weight Control - WebMD, 10/12/11 - "men and women fed a 10% protein diet ate 12% more calories over four days than they did on a 15% protein diet ... When protein in the diet goes too low, ''We keep eating in an attempt to attain our target level of protein," ... As the protein declined to 10%, the men and women tended to eat more carbohydrates and fat-containing food, boosting the risk for weight gain. But Gosby found that increasing the protein from 15% to 25% didn't seem to make any difference in total calories eaten ... Aiming at 15%-25% of total energy intake as protein seems about right for a moderately active person" - [Science Daily]
• High-Protein Diet Raises Type 2 Diabetes Risk - Medscape, 9/13/11 - "The study consisted of 27,140 individuals 45 to 74 years of age who participated in the Malmö Diet and Cancer study ... the researchers found a 37% increased risk for type 2 diabetes associated with high protein intake (hazard ratio [HR], 1.37; 95% confidence interval [CI], 1.17 to 1.61; P for trend < .001]. High intake of processed meat was also associated with an elevated risk for diabetes (HR, 1.17; 95% CI, 1.00 to 1.36; P for trend = .005) ... The intake of breads and cereals rich in fiber was associated with a lower risk of developing diabetes (HR, 0.95; 95% CI, 0.92 to 0.98; P for trend = .005)"
• Eating protein throughout the day preserves muscle and physical function in dieting postmenopausal women, study suggests - Science Daily, 8/10/11 - "higher protein intake during weight loss can offset negative effects on muscle mass by maintaining more muscle relative to the amount of weight lost. Women who ate more protein lost 3.9 percent more weight and had a relative gain of 5.8 percent more thigh muscle volume than woman who did not ... 31 healthy, postmenopausal obese women were divided into two groups. Each group followed a 1,400-calorie weight-loss diet based on USDA's My Pyramid, but one group received a powdered whey protein supplement in the morning and again in the afternoon or evening; the other received a placebo that contained carbohydrates ... We hypothesize that more vigorous exercise -- in particular, resistance training -- would preserve even more muscle" - See whey protein at Amazon.com or try the yogurt recipe at the top of my yogurt page.
• Low-carbohydrate, high-protein diets may reduce both tumor growth rates and cancer risk - Science Daily, 6/14/11 - "The first diet, a typical Western diet, contained about 55 percent carbohydrate, 23 percent protein and 22 percent fat. The second, which is somewhat like a South Beach diet but higher in protein, contained 15 percent carbohydrate, 58 percent protein and 26 percent fat. They found that the tumor cells grew consistently slower on the second diet ... As well, mice genetically predisposed to breast cancer were put on these two diets and almost half of them on the Western diet developed breast cancer within their first year of life while none on the low-carbohydrate, high-protein diet did. Interestingly, only one on the Western diet reached a normal life span (approximately 2 years), with 70 percent of them dying from cancer while only 30 percent of those on the low-carbohydrate diet developed cancer and more than half these mice reached or exceeded their normal life span ... tumor cells, unlike normal cells, need significantly more glucose to grow and thrive. Restricting carbohydrate intake can significantly limit blood glucose and insulin, a hormone that has been shown in many independent studies to promote tumor growth in both humans and mice"
• Protein drinks after exercise help maintain aging muscles - Science Daily, 5/26/11 - "protein drinks after aerobic activity increases the training effect after six weeks, when compared to carbohydrate drinks. Additionally, this study suggests that this effect can be seen using as little as 20 grams of protein"
• High-Protein Diet Limits Bone Resorption - Doctor's Guide, 10/19/10 - "The clinical takeaway message is that if you are a postmenopausal woman and dieting, if you can take 24% of your total calories as protein, and have adequate calcium and vitamin D, you can prevent the bone loss that is typically associated with weight loss"
• Animal-Based Low-Carbohydrate Diet Linked to Higher All-Cause Mortality - Medscape, 9/7/10 - "In a pooled analysis comparing the lowest vs the highest deciles, overall low-carbohydrate score was associated with a slight increase in overall mortality rates (hazard ratio [HR], 1.12; 95% confidence interval [CI], 1.01 - 1.24; P for trend = .136). Higher animal-based low-carbohydrate score was associated with higher all-cause mortality rates (pooled HR, 1.23; 95% CI, 1.11 - 1.37; P for trend = .051), cardiovascular deaths (HR, 1.14; 95% CI, 1.01 - 1.29; P for trend = .029), and cancer-related deaths (corresponding HR, 1.28; 95% CI, 1.02 - 1.60; P for trend = .089) ... In contrast, higher vegetable-based low-carbohydrate score was linked to reduced all-cause mortality rates (HR, 0.80; 95% CI, 0.75 - 0.85; P for trend ≤ .001) and cardiovascular deaths (HR, 0.77; 95% CI, 0.68 - 0.87; P for trend < .001)"
• High-protein diets may cause bone loss in older women, study - Nutra USA, 7/8/10 - "Study 1 ... on average, all women lost around 19 pounds, but those who ate the higher-protein, meat-containing diet also lost bone mineral density by about 1.4 percent ... Study 2 ... All women lost weight, but the groups that consumed the higher-protein meat-containing diets again also lost bone mineral density by up to 1.4 percent compared to the control group ... In the first study, all the participants con&shy;sumed calcium supplements to achieve calcium intakes of 2,000mg per day. In the second study, about half of the participants con&shy;sumed calcium supplements ... However, in neither case were the supplements found to impact the loss of bone density"
• Eat less, live longer? - New Scientist, 6/3/10 - "One piece of evidence for this idea comes from studies in fruit flies and rodents. If these animals are fed special diets with less amino acids - the building blocks of proteins - they can eat as many calories as they want and still live longer ... The protein theory is bad news for people on low-carbohydrate weight-loss plans like the Atkins diet. "I'd be wary of diets that put a heavy emphasis on protein," says Piper. "It's hard to see how that could be healthy." Fontana goes one step further, saying that high-protein diets could risk accelerated ageing and cancer ... There may be another reason for vegans to celebrate. Studies on flies and rodents suggest that cutting intake of one particular amino acid, called methionine, lengthens life to a similar degree as calorie restriction. Proteins in meat and other animal products have high levels of methionine, so a vegan diet would score well by that measure, too"
• Dietary protein may reduce hip fractures in the elderly - Science Daily, 5/5/10 - "individuals who were in the lowest 25 percent of dietary protein intake had approximately 50 percent more hip fractures than those who consumed greater amounts of dietary protein (all within normal intakes). Those who suffered hip fractures consumed less than the 46 grams of dietary protein per day recommended for adults"
• 'Anti-Atkins' Low Protein Diet Extends Lifespan In Flies - Science Daily, 10/1/09 - Science Daily, 10/1/09 - "Flies fed an "anti-Atkins" low protein diet live longer because their mitochondria function better"
• High-Carb, High-Fat Diets Better for Cognitive Performance - Medscape, 9/1/09 - "Diets high in carbohydrates or fat can lead to significantly better cognitive-performance and inflight-testing scores in pilots than diets high in protein"
• Low-carb Diets Linked To Atherosclerosis And Impaired Blood Vessel Growth - Science Daily, 8/25/09 - "Even as low-carbohydrate/high-protein diets have proven successful at helping individuals rapidly lose weight, little is known about the diets' long-term effects on vascular health ... mice placed on a 12-week low carbohydrate/high-protein diet showed a significant increase in atherosclerosis, a buildup of plaque in the heart's arteries and a leading cause of heart attack and stroke ... our research suggests that, at least in animals, these diets could be having adverse cardiovascular effects that are not reflected in simple serum markers"
• Recipe for Diabetes: Too Much Protein, Fat - WebMD, 4/7/09 - "A high-fat diet may lead to insulin resistance, a major step on the path to type 2 diabetes. But cutting back on fat may not help those who continue to eat too much protein"
• Eating Red, Processed Meat Associated With Increased Risk of Death From All Causes - Doctor's Guide, 3/23/09 - "When comparing the one-fifth of participants who ate the most white meat to the one-fifth who ate the least white meat, those with high white meat intake had a slightly lower risk for total death, death from cancer and death from causes other than heart disease or cancer ... For overall mortality, 11% of deaths in men and 16% of deaths in women could be prevented if people decreased their red meat consumption to the level of intake in the first quintile ... The impact on cardiovascular disease mortality was an 11% decrease in men and a 21% decrease in women if the red meat consumption was decreased to the amount consumed by individuals in the first quintile. For women eating processed meat at the first quintile level, the decrease in cardiovascular disease mortality was approximately 20%" - [Science Daily]
• Calcium And Vitamin D May Not Be The Only Protection Against Bone Loss - Science Daily, 12/3/08 - "Diets that are high in protein and cereal grains produce an excess of acid in the body which may increase calcium excretion and weaken bones ... When fruits and vegetables are metabolized they add bicarbonate, an alkaline compound, to the body ... bicarbonate had a favorable effect on bone resorption and calcium excretion ... 171 men and women aged 50 and older were randomized to receive placebo or doses of either: potassium bicarbonate, sodium bicarbonate, or potassium chloride for three months. Researchers found that subjects taking bicarbonate had significant reductions in calcium excretion, signaling a decrease in bone resorption"
• Optimal protein intake in the elderly - Clin Nutr. 2008 Sep 24 - "It appears that an intake of 1.5gprotein/kg/day, or about 15-20% of total caloric intake, is a reasonable target for elderly individuals wishing to optimize protein intake in terms of health and function"
• Protein + Exercise May Promote Weight Loss - WebMD, 8/29/05 - "obese women who exercised regularly and ate a reduced-calorie diet high in protein lost more fat and less muscle than those who ate a similar diet high in carbohydrates. Both diets contained the same number of total calories and percentage of calories from fat"
• Improved Glucose Response with High-protein Diet in Individuals with Type 2 Diabetes - Doctor's Guide, 10/16/03 - "either a control diet designed according to the recommendations of the American Diabetes Association (protein:carbohydrate:fat, 15:55:30) or a high-protein diet (30:40:30) for a period of 5 weeks ... fasting glucose concentration was consistently lower after the high-protein diet, with no significant change in body weight. The mean 24-hour integrated glucose area responses (with fasting glucose concentration as baseline) were 34.1 +/- 7.2 mmol x h/L and 21.0 +/- 4.2 mmol x h/L after the control and high-protein diets, respectively, revealing a 40% decrease with the high-protein diet"
• High-Protein Diet Helpful in Type 2 Diabetes - Medscape, 10/6/03 - "The ratio of protein to carbohydrate to fat was 30:40:30 in the high-protein diet and 15:55:30 in the control diet ... there was a 40% decrease in the mean 24-hour integrated glucose area response after the high-protein diet. Patients on the high-protein diet also fared better in terms of decrease in glycated hemoglobin ... longer-term studies are necessary to determine the total magnitude of response, possible adverse effects, and the long-term acceptability of the diet"
• High Protein Diets More Effective At Maintaining Weight Loss - Doctor's Guide, 6/4/03 - "Despite no differences in attitudes to eating, a protein intake of 18% as energy versus 15% as energy resulted in improved weight maintenance, as well as improved fat distribution based on body waist circumference, and improved substrate oxidation and satiety"
• Interaction of Dietary Calcium and Protein in Bone Health in Humans - J. Nutr. 133:852S-854S, 3/03 - "Protein has both positive and negative effects on calcium balance, and the net effect of dietary protein on bone mass and fracture risk may be dependent on the dietary calcium intake. In addition to providing substrate for bone matrix, dietary protein stimulates the production of insulin-like growth factor-1 (IGF-1), a factor that promotes osteoblast-mediated bone formation. Protein also increases urinary calcium losses, by several proposed mechanisms. Increasing calcium intake may offset the negative impact of dietary protein on urinary calcium losses, allowing the favorable effect of protein on the IGF-1 axis to dominate"
• Protein Diet May Prompt Weight Loss - WebMD, 2/7/03 - "The study was funded by beef producers and Kraft Foods, which makes dairy products, as well as the USDA and Illinois Council on Food and Agricultural Research ... "However, what concerns me is that in this study, they provided all the food for four weeks so they could make sure the participants that were getting more protein got very lean meat. They also received intensive counseling for the next six weeks ... and they still didn't have as good cholesterol reductions as those eating what is a typical diet," she tells WebMD. "If you tell someone to eat seven servings of beef a week, I doubt they will be as careful in choosing the leanest cuts of beef, and as a result, they may consume even more saturated fat and dietary cholesterol. What's more, if I was counseling someone to eat more protein to get leucine, I would stress baked or broiled fish, nonfat dairy products, and legumes.""
• Low-Carbohydrate, High-Protein Diets: Are They Safe? - New Hope Natural Media, 12/5/02 - "Low-carbohydrate, high-protein diets are known to suppress the appetite and to curb feelings of hunger, which is why many people lose weight on these types of diets. However, consuming these diets can result in the depletion of minerals such as potassium and magnesium, which are needed to maintain a normal heart rhythm. This mineral-losing effect may be compounded when the daily calorie intake is restricted"
• American Heart Association Statement on High-Protein, Low-Carbohydrate Diet Study Presented at Scientific Sessions - AHA, 11/19/02
• Experts ping-pong on protein advice - MSNBC, 10/22/02 - "Now protein can range from 10 percent to 35 percent of daily intake. At the annual meeting of the American Dietetic Association this week, nutritionists basically admitted that they really don’t know how much protein Americans need ... Studies have shown that you need to get at least 76 grams of protein, so that means you have to go to the upper ranges of the protein recommendations for a 1,200 calorie diet"
• High Protein Diet Helps Control Blood Glucose in Untreated Type 2 Diabetics - Doctor's Guide, 9/5/02
• Low-Carbohydrate, High-Protein Diets Increase Risk Of Kidney Stones And May Raise Bone Loss Risk - Doctor's Guide, 8/1/02 - "acid excretion - a marker for the acid load in the blood - increased as much as 90 percent while subjects were on diets that severely restricted carbohydrates. Levels of urinary citrate, which inhibits kidney stones, fell by almost 25 percent in the group during the six-week study ... People may lose weight on this diet, but this study shows that this is not a healthy way to lose weight ... there was an increased risk of developing kidney stones and a possible increase in the risk of bone loss"
• High-Protein Diet Could Repair Bone Loss - WebMD, 3/25/02 - "The supplement group -- particularly those who ate a diet high in protein -- had significantly better bone mass density -- an accurate measure of bone loss. Those who took the placebo, however, had less calcium absorbed into their bloodstream when they consumed more protein"
• High-Protein Beats High-Carbohydrate for Weight Loss in Low-Fat Diets - Doctor's Guide, 2/26/02 - "Measurements taken after a 10 hour fast and at 2.5-hour post breakfast, lunch and dinner showed that postprandial thermogenesis averaged about twofold higher on the high-protein against the high-carbohydrate diet ... Nitrogen balance on the high protein diet was found to be significantly greater than the high-carbohydrate diet"
• Mother's Diet During Pregnancy May Influence Child's Blood Pressure Later In Life - Intelihealth, 1/17/02 - "Pregnant women who consume a diet rich in animal protein and low in carbohydrates may be more likely to have children with elevated blood pressure later in life"
• Health Experts Advise Against High-Protein Diets - WebMD, 10/8/01
• Prone to Kidney Stones? Watch What You Eat - WebMD, 7/20/01 - "On average, the men with a history of kidney stones developed higher levels of oxalate in their urine while on the high protein diet compared with the medium protein diet"
• Many Parents Are Confused About What to Feed Growing Athletes - WebMD, 7/6/01 - "The survey of parents of 6- to 12-year-old athletes, conducted by the American Dietetic Association's sports group, SCAN (Sports, Cardiovascular and Wellness Nutritionists) found that 60% said athletic kids need lots of protein to increase muscle size. However, such kids actually need a diet rich in breads, cereals, pasta, and other carbohydrates because carbs are the body's main energy source for exercise and the major fuel for the brain ... "Despite the popular myth, extra protein doesn't mean bigger muscles because muscle size is dependent on calories, physical maturity, genetics, and training," she tells WebMD. The athletic kid's diet ratio should be 50-55% carbohydrate, 10-15% protein and 30% fat"
• Pregnant Women Need a Balanced Diet That's 'Just Right' - WebMD, 6/1/01 - "Women given supplements containing large amounts of protein actually had babies that were smaller on average than women who did not take the supplements. That led the government, which sets the Recommended Daily Allowance (RDA), to lower its recommended level of daily protein for pregnant women from 74 grams per day to 60 grams"

Abstracts:

• The role of protein intake in the relationship between egg consumption and body composition in young adults. A mediation analysis - Clin Nutr 2022 Sep 6 - "The association between egg consumption and body composition is mediated by protein intake. This finding is important from a public health perspective, suggesting that higher egg consumption (≥5 eggs/week) may lead to a healthier body composition, especially due to higher protein intake" - Note: I eat a couple scrambled eggs per day. Love my Hexclad frying pan. I spay it with avocado oil.
• Clinical implications of low estimated protein intake in patients with heart failure - J Cachexia Sarcopenia Muscle 2022 Apr 14 - "An estimated lower protein intake was associated with a lower BMI, but signs of congestion were more prevalent. A lower estimated protein intake was independently associated with a higher mortality risk"
• Adequate Protein Intake on Comprehensive Frailty in Older Adults: Kyoto-Kameoka Study - J Nutr Health Aging 2022 - "actual body weight (BW) ... The association between protein intake and comprehensive frailty was also evaluated using curve fitting with non-linear regression, a weak U-shaped association was found in males and an L-shaped association in females. Men had a low prevalence of frailty at a calibrated protein intake of 15-17% energy from protein, 1.2 g/kg actual BW/day, or 1.4 g/kg ideal BW/day, and women had a low prevalence of frailty at 17-21% energy from protein or 1.6 g/kg ideal BW/day, with the prevalence of frailty remaining unchanged at higher protein intakes. Meanwhile, the inverse relationship between protein intake per ABW and frailty showed a gradual decrease at 1.4 g/kg ABW/day for protein in women"
• Protein intake and muscle mass maintenance in patients with cancer types with high prevalence of sarcopenia: a systematic review - Support Care Cancer 2021 Oct 25 - "Cancer is associated with muscle wasting. However, optimal protein intake has not been determined, limiting the efficacy of nutritional interventions ... Our findings show that protein intakes below 1.2 g/kg, even when within the recommendations, have been associated with muscle wasting during treatment. Only intakes above 1.4 g/kg have been associated with muscle maintenance. High-quality research is needed to establish an optimal dose response"
• The cost effectiveness of personalized dietary advice to increase protein intake in older adults with lower habitual protein intake: a randomized controlled trial - Eur J Nutr 2021 Oct 5;1-16 - "Dietary advice to increase protein intake to ≥ 1.2 g/kg aBW/d improved 400-m walk time and leg strength among older adults with a lower habitual protein intake. From a societal perspective, PROT was considered cost-effective compared to CON" - [Nutra USA]
• Long-term dietary protein intake and subjective cognitive decline in US men and women - Am J Clin Nutr 2021 Jul 22 - "subjective cognitive decline (SCD) ... Higher protein intake was associated with lower odds of SCD when compared isocalorically with carbohydrate. Plant protein sources were also associated with lower odds when compared with animal protein sources. Our findings suggest that adequate protein intake, and choices of protein sources could play a role in the maintenance of cognition and should be studied further"
• Is protein the forgotten ingredient: Effects of higher compared to lower protein diets on cardiometabolic risk factors. A systematic review and meta-analysis of randomised controlled trials - Atherosclerosis 2021 May 26 - "Higher protein (HP) diets may lead to lower cardiometabolic risk, compared to lower protein (LP) diets. This systematic review and meta-analysis aims to investigate the effects of HP versus LP diets on cardiometabolic risk factors in adults, using the totality of the current evidence from randomised controlled trials (RCTs) ... Higher protein diets showed small, but favourable effects on weight loss, fat mass loss, systolic blood pressure, some lipid outcomes and insulin, compared to lower protein diets"
• Dietary protein intake, kidney function, and survival in a nationally representative cohort - Am J Clin Nutr 2021 Mar 19 - "High-protein diets (e.g., Paleo, Atkins, South Beach, ketogenic) have gained popularity as a means to promote weight loss and avoid excess carbohydrate consumption. Yet in chronic kidney disease (CKD) patients, evidence suggests low dietary protein intake (DPI) leads to attenuation of kidney function decline, although concerns remain for risk of protein-energy wasting ... high biological value (HBV) protein ... Among participants with impaired kidney function, a higher DPI and greater HBV consumption were associated with higher mortality, whereas a lower DPI was associated with higher mortality in those with normal kidney function"
• Intermittent Fasting with a High Protein Diet Mitigated Osteoarthritis Symptoms by Increasing Lean Body Mass and Reducing Inflammation in Osteoarthritic rats with Alzheimer's Disease-Like Dementia - Br J Nutr 2021 Mar 10 - "Alzheimer's-like disease (AD) ... intermittent fasting(IMF) ... high-protein(H-P) ... high-fat(H-F) or H-P diets for two weeks ... AD exacerbated the articular cartilage deterioration and memory impairment, and IMF with H-P alleviated the memory impairment and osteoarthritic symptoms by decreasing hippocampal amyloid-β deposition and proinflammatory cytokine expressions and by increasing LBM"
• Effect of dietary protein intake on bone mineral density and fracture incidence in older adults in the Health, Aging, and Body Composition study - J Gerontol A Biol Sci Med Sci 2021 Mar 3 - "Dietary recommendations may underestimate the protein older adults need for optimal bone health. This study sought to determine associations of protein intake with bone mineral density (BMD) and fracture among community-dwelling white and black older adults ... Participants in the upper protein tertile (≥15% TEI) had 1.8-6.0% higher mean hip and lumbar spine BMD compared to the lower protein tertile (<13% TEI; p<0.05). Protein intake did not affect change in BMD at any site over the follow-up period. Participants in the upper protein tertile had a reduced risk of clinical vertebral fracture over five years of follow-up (Hazard Ratio: 0.36 [95% Confidence Intervals (CI), 0.14, 0.97] vs. lower protein tertile ... Older adults with higher protein intake (≥15% TEI) had higher BMD at the hip, whole body, and lumbar spine, and a lower risk of vertebral fracture"
• Prevalence of low protein intake in 80+ year-old community-dwelling adults and association with dietary patterns and modifiable risk factors- a cross-sectional study - Br J Nutr 2021 Mar 8 - "Low protein intake may accelerate age-related loss of lean mass and physical function. We investigated prevalence of low protein intake (<1.0 g/kg/day) and the associations between dietary patterns, key modifiable risk factors and low protein intake in self-reliant community-dwelling adults ≥ 80 years ... Participants with low protein intake had a higher prevalence of nausea, diarrhoea and mouth dryness. Reduced appetite, mouth dryness and pain increased odds of low protein intake (adjusted OR 3.06 CI: 1.23-7.63, OR 3.41 CI:1.51-7.7, OR 1.54 CI:1.00-2.36, respectively). There was a high prevalence of low protein intake in community-dwelling adults ≥ 80-years. Day-to-day variability, reduced appetite, mouth dryness and pain may be potentially modifiable risk factors. Targeting dietary patterns and risk factors in primary prevention strategies may be important to improve intake of protein and minimise risk of physical frailty"
• The Association between Dietary Amino Acid Intake and Cognitive Decline 8 Years Later in Japanese Community-Dwelling Older Adults - J Nutr Health Aging 2021 - "Cognitive decline was present in 133 (31.1%) participants. After adjustment for covariates, including total protein intake, the ORs (95% CIs) for cognitive decline were 2.40 (1.21-4.75) for lysine, 2.05 (1.02-4.09) for phenylalanine, 2.18 (1.09-4.34) for threonine, and 2.10 (1.06-4.15) for alanine ... Conclusion: The results suggest that lysine, phenylalanine, threonine, and alanine intake is important for the maintenance of cognitive function in older people, independent of total protein intake"
• Protein supplementation increases adaptations to endurance training: A systematic review and meta-analysis - Clin Nutr 2020 Dec 15 - "Nineteen studies and 1162 participants contributed to the analyses. Compared with the control group, the protein supplementation group demonstrated greater improvements in aerobic capacity measured by mixed peak oxygen uptake (V̇O2peak) and peak workload power (Wpeak) (standardised mean difference [SMD] = 0.36, 95% confidence interval [CI]: 0.05 to 0.67), and V̇O2peak (mean difference [MD] = 0.89 mL‧kg-1‧min-1, 95% CI: 0.07 to 1.70); had a greater lean mass gain (MD = 0.32 kg, 95% CI: 0.07 to 0.58); and had a greater improvement in time trial performance (MD = -29.1s, 95% CI:-55.3 to -3.0). Secondary analyses showed that, in addition to the substantial improvement in V̇O2peak (MD = 3.67 mL‧kg-1‧min-1, 95% CI: 2.32 to 5.03) attributed to endurance training, protein supplementation provided an additional 26.4% gain in V̇O2peak (MD = 0.97 mL‧kg-1‧min-1, 95% CI: -0.03 to 1.97) ... Protein supplementation further increased aerobic capacity, stimulated lean mass gain, and improved time trial performance during chronic endurance training in healthy and clinical populations" - See whey protein at Amazon.com.
• Nutrients to mitigate osteosarcopenia: the role of protein, vitamin D and calcium - Curr Opin Clin Nutr Metab Care 2020 Nov 2 - "An adequate intake of protein (1.2-1.5 g/kg/day), vitamin D (800 IU/day) and calcium (1000-1200 mg/day), is well tolerated and effective at mitigating some aspects of osteosarcopenia such as lean mass, bone density and fracture risk" - See vitamin D at Amazon.com and vitamin D at iHerb.
• Number of high-protein containing meals correlates with muscle mass in pre-frail and frail elderly - Eur J Clin Nutr. 2020 Apr 7 - "Protein intake and number of meals with either ≥20 g or ≥30 g of protein were significantly associated (after controlling for confounding factors) with greater total and appendicular lean mass and vastus lateralis CSA ... We found that not only total protein intake but also the number of high-protein containing meals are associated with muscle mass in frail and pre-frail elderly"
• Anabolic response to essential amino acid plus whey protein composition is greater than whey protein alone in young healthy adults - J Int Soc Sports Nutr. 2020 Feb 10;17(1):9 - "essential amino acids ... We conclude that a composition of a balanced EAA formulation combined with whey protein is highly anabolic as compared to a whey protein-based recovery product, and that the response is dose-dependent"
• Association between Dietary Protein Intake and Cognitive Function in Adults Aged 60 Years and Older - J Nutr Health Aging. 2020;24(2):223-229 - "Protein intake was positively associated with cognitive function. In full-adjusted model, the significant association between dietary protein intake and Recall Test score was observed (quartile (Q) 2 versus Q1, β=0.24, 95%CI: 0.01 to 0.47); the association between protein intake and Animal Fluency test was significant (Q2 versus Q1, β=1.40, 95%CI: 0.51 to 2.29; Q4 versus Q1, β=1.42, 95%CI: 0.37 to 2.48); the positive associations with DSST score and Composite z-score were observed both in Q2 versus Q1 and Q3 versus Q1 of protein intake. Protein intake from total animal, total meat, eggs and legumes were associated with a better performance on certain cognitive tests. However, an adverse association between higher protein intake from milk and milk products and cognitive function was observed"
• High Protein Intake Is Associated with Lower Risk of All-Cause Mortality in Community-Dwelling Chinese Older Men and Women - J Nutr Health Aging. 2019 - "Contrary to findings from Caucasian populations of all ages, among Chinese older adults, higher total protein intake was associated with lower all-cause and cancer mortality in Chinese older men. While higher animal protein intake was associated with reduced all-cause mortality in Chinese older men, higher plant protein intake was protective against all-cause mortality in Chinese women. The attenuated associations between protein intake and mortality risk after adjustment for other dietary variables also highlight the role of whole diet approach in mortality risk reduction among older adults"
• Protein Intake to Maximize Whole-Body Anabolism during Postexercise Recovery in Resistance-Trained Men with High Habitual Intakes is Severalfold Greater than the Current Recommended Dietary Allowance - J Nutr. 2019 Oct 16 - "A breakpoint protein intake of ~2.0 g.kg-1.d-1, which maximized whole-body anabolism in resistance-trained men after exercise, is greater than previous IAAO-derived estimates for nonexercising men and is at the upper range of current general protein recommendations for athletes. The capacity to enhance whole-body net balance may be greater than previously suggested to maximize muscle protein synthesis in resistance-trained athletes accustomed to a high habitual protein intake"
• The combination of sport and sport-specific diet is associated with characteristics of gut microbiota: an observational study - J Int Soc Sports Nutr. 2019 May 3 - "Results suggest that high-protein diets may have a negative impact on gut microbiota diversity for athletes, while athletes in resistance sports that carry out the high protein low carbohydrates diet demonstrate a decrease in short chain fatty acid-producing commensal bacteria" - [Nutra USA]
• Protein supplementation improves lean body mass in physically active older adults: a randomized placebo-controlled trial - J Cachexia Sarcopenia Muscle. 2019 Mar 7 - "A randomized double-blinded controlled trial was performed among 116 physically active older adults [age 69 (interquartile range: 67-73) years, 82% male] who were training for a 4 day walking event of 30, 40, or 50 km/day. Participants were randomly allocated to either 31 g of milk protein or iso-caloric placebo supplementation for 12 weeks ... In physically active older adults with relatively low habitual dietary protein consumption, an improvement in physical performance, an increase in lean body mass, and a decrease in fat mass were observed after walking exercise training. A larger increase in relative lean body mass and larger reduction in fat mass were observed in participants receiving 12 weeks of daily protein supplementation compared with controls, whereas this was not accompanied by differences in improvements between groups in muscle strength and physical performance"
• Protein supplementation enhances cerebral oxygenation during exercise in elite basketball players - Nutrition. 2018 Feb 5;53:34-37 - "supplements with different whey protein contents ... resulted in a 16% longer cycling time (from 474 ± 49 s to 553 ± 78 s, P < 0.05), compared with the low-protein trial" - [Nutra USA] - See whey protein at Amazon.com.
• Intake of a Protein-Enriched Milk and Effects on Muscle Mass and Strength. A 12-Week Randomized Placebo Controlled Trial among Community-Dwelling Older Adults - J Nutr Health Aging. 2017;21(10):1160-1169 - "Increased protein intake (2 x 20 g/d) did not significantly improve muscle mass, muscle strength or functional performance in healthy older weight stable adults. Whether intake of > 20 g protein to each meal is necessary for preservation of muscle mass and strength in older adults should be further investigated in a larger study. This underscores the need for well-designed studies that can differentiate between the effect of protein intake and increased energy"
• Soluble Milk Proteins Improve Muscle Mass Recovery after Immobilization-Induced Muscle Atrophy in Old Rats but Do not Improve Muscle Functional Property Restoration - J Nutr Health Aging. 2017;21(10):1133-1141 - "Whey proteins and soluble milk proteins improve muscle mass recovery after immobilization-induced muscle atrophy in old rats but do not allow muscle functional property restoration"
• Effects of Aerobic and Resistance Training Combined with Fortified Milk on Muscle Mass, Muscle Strength, and Physical Performance in Older Adults: A Randomized Controlled Trial - J Nutr Health Aging. 2017;21(10):1349-1357 - "Fortified milk and resistance training (RT) increase muscle mass, muscle strength, and physical performance in older adults, but it remains unclear whether RT combined with aerobic training (AT) would have stronger effects on these outcomes. The purpose of this study was to examine the effects of aerobic and resistance training (ART) combined with fortified milk consumption on muscle mass, muscle strength, and physical performance in older adults ... These results suggest that AT before RT combined with fortified milk consumption has similar effects on skeletal muscle mass and strength compared with RT alone, but it may be a more useful strategy to improve physical performance in older adults. Although the mechanism of our intervention is uncertain, our program would be an effective prevention for sarcopenia in older adults"
• Effects of Supplementation with Beef or Whey Protein Versus Carbohydrate in Master Triathletes - J Am Coll Nutr. 2017 Sep 14:1-9 - "After being randomly assigned to one of the following groups-beef, whey, or carbohydrate-24 master-age (35-60 years old) male triathletes (n = 8 per treatment) ingested 20 g of supplement mixed with plain water once a day (immediately after training or before breakfast) ... Only beef significantly reduced body mass (p = 0.021) along with a trend to preserve or increase thigh muscle mass (34.1 ± 6.1 vs 35.5 ± 7.4 mm). Both whey (38.4 ± 3.8 vs 36.9 ± 2.8 mm) and carbohydrate (36.0 ± 4.8 vs 34.1 ± 4.4 mm) interventions demonstrated a significantly (p < 0.05) decreased vastus medialis thickness Additionally, the beef condition produced a significant (p < 0.05) increase in ferritin concentrations (117 ± 78.3 vs 150.5 ± 82.8 ng/mL) ... Ingesting a hydrolyzed beef protein beverage after workout or before breakfast (nontraining days) can be effective in preserving thigh muscle mass and in improving iron status in male master-age triathletes" - See hydrolyzed beef protein powder at Amazon.com.
• Association of Protein Intake with Bone Mineral Density and Bone Mineral Content among Elderly Women: The OSTPRE Fracture Prevention Study - J Nutr Health Aging. 2017;21(6):622-630 - "bone mineral content (BMC) .. bone mineral density (BMD) ... total protein (TP), animal protein (AP) and plant protein (PP) ... TP (P≤0·029) and AP (P≤0·045) but not PP (g/d) were negatively associated with femoral neck (FN) BMD and BMC ... TP (g/kg/BW) was inversely associated with LS BMD and LS BMC ... This study suggests detrimental associations between protein intake and bone health"
• Effect of high-protein meal replacement on weight and cardiometabolic profile in overweight/obese Asian Indians in North India - Br J Nutr. 2017 Jun 2 - "high-protein meal replacement (HPMR) ... These findings show that intervention with HPMR may lead to significant weight loss and improvement in obesity measures, metabolic, lipid and inflammatory parameters and hepatic transaminases in overweight/obese Asian Indians"
• International Society of Sports Nutrition Position Stand: protein and exercise - Journal of the International Society of Sports Nutrition, Jun 3, 2017 - "muscle protein synthesis (MPS) ... Acute protein doses should strive to contain 700–3000 mg of leucine and/or a higher relative leucine content, in addition to a balanced array of the essential amino acids (EAAs) ... Rapidly digested proteins that contain high proportions of essential amino acids (EAAs) and adequate leucine, are most effective in stimulating MPS" - [Nutra USA] - See BulkSupplements Pure L-Leucine Powder (1 Kilogram).
• High-Protein Foods and Physical Activity Protect Against Age-Related Muscle Loss and Functional Decline - J Gerontol A Biol Sci Med Sci. 2017 May 25 - "Higher intakes of protein-source foods (red meat, poultry, fish, dairy, and soy, nuts, seeds and legumes) were associated with higher %SMM over 9 years, particularly among women. Men and women with higher intakes of foods from animal sources had a higher % SMM regardless of activity; beneficial effects of plant-based protein foods were only evident in physically active adults. Active subjects with higher intakes of animal or plant protein-source foods had 35% lowest risks of functional decline. Among less active individuals, only those consuming more animal protein-source foods had reduced risks of functional decline (HR: 0.7l" - See BulkSupplements Pure L-Leucine Powder (1 Kilogram).
• Diet with a combination of high protein and high total antioxidant capacity is strongly associated with low prevalence of frailty among old Japanese women: a multicenter cross-sectional study - Nutr J. 2017 May 12;16(1):29 - "total antioxidant capacity (TAC) ... Multivariate adjusted ORs (95% CIs) for frailty in the highest compared to the lowest tertile were 0.66 (0.49, 0.87) for total protein intake (P for trend = 0.003) and 0.51 (0.37, 0.69) for dietary TAC (P for trend <0.0001) after adjustment for dietary TAC or total protein intake, respectively"
• The Association between Total Protein and Vegetable Protein Intake and Low Muscle Mass among the Community-Dwelling Elderly Population in Northern Taiwan - Nutrients. 2016 Jun 17;8(6) - "Sarcopenia, highly linked with fall, frailty, and disease burden, is an emerging problem in aging society. Higher protein intake has been suggested to maintain nitrogen balance ... Participants with diets in the lowest quartile of total protein density (<13.2%) were at a higher risk for low muscle mass (odds ratio (OR) 3.03, 95% confidence interval (CI) 1.37-6.72) than those with diets in the highest quartile (≥17.2%). Similarly, participants with diets in the lowest quartile of vegetable protein density (<5.8%) were at a higher risk for low muscle mass (OR 2.34, 95% CI 1.14-4.83) than those with diets in the highest quartile (≥9.4%). Furthermore, the estimated skeletal muscle mass index increased significantly across the quartiles of total protein density (p = 0.023) and vegetable protein density (p = 0.025). Increasing daily intakes of total protein and vegetable protein densities appears to confer protection against pre-sarcopenia status"
• Association Between Protein Intake and Mortality in Hypertensive Patients Without Chronic Kidney Disease in the OLD-HTA Cohort - Hypertension. 2016 Apr 18 - "A total of 1128 hypertensive patients were followed according to tertile of protein intake adjusted for ideal body weight: <0.70, 0.70 to 0.93, and >0.93 g/kg ... 10 years of follow-up ... patients in the second and third tertiles of protein intake had a decreased risk of all-cause death (hazard ratio [95% confidence interval], 0.71 [0.56-0.91]) and cardiovascular death (0.72 [0.54-0.96]), but not of stroke death (0.72 [0.41-1.28]) in comparison to patients in the low protein intake tertile. Normal-high protein intake was associated with a better outcome in a subset of the population ... Hypertensive patients having a protein intake >0.7 g/kg ideal body weight, particularly those at low risk, had lower all-cause and cardiovascular mortality rates. Physicians may encourage hypertensive patients to have normal or high protein diet in addition to low salt consumption, moderate alcohol consumption, and regular physical activity"
• Per meal dose and frequency of protein consumption is associated with lean mass and muscle performance - Clin Nutr. 2016 Apr 7 - "We found that more frequent consumption of meals containing between 30 and 45 g protein/meal produced the greatest association with leg lean mass and strength. Thus, the consumption of 1-2 daily meals with protein content from 30 to 45 g may be an important strategy for increasing and/or maintaining lean body mass and muscle strength with aging"
• Higher compared with lower dietary protein during an energy deficit combined with intense exercise promotes greater lean mass gain and fat mass loss: a randomized trial - Am J Clin Nutr. 2016 Mar;103(3):738-46 - "lean body mass (LBM) ... control diet (CON) or a higher-protein (2.4 g · kg(-1) · d(-1)) diet (PRO) ... LBM increased (P < 0.05) in the PRO group (1.2 ± 1.0 kg) and to a greater extent (P < 0.05) compared with the CON group (0.1 ± 1.0 kg). The PRO group had a greater loss of fat mass than did the CON group (PRO: -4.8 ± 1.6 kg; CON: -3.5 ± 1.4kg; P < 0.05). All measures of exercise performance improved similarly in the PRO and CON groups as a result of the intervention with no effect of protein supplementation. Changes in serum cortisol during the intervention were associated with changes in body fat (r = 0.39, P = 0.01) and LBM" - [Nutra USA]
• Macronutrients Intake and Incident Frailty in Older Adults: A Prospective Cohort Study - J Gerontol A Biol Sci Med Sci. 2016 Mar 4 - "monounsaturated fatty acids (MUFAs) ... Intake of total protein, animal protein, and MUFAs was inversely associated with incident frailty. Promoting the intake of these nutrients might reduce frailty"
• The Colonic Microbiome and Epithelial Transcriptome Are Altered in Rats Fed a High-Protein Diet Compared with a Normal-Protein Diet - J Nutr. 2016 Feb 3 - "A high-protein diet (HPD) can produce hazardous compounds and reduce butyrate-producing bacteria in feces, which may be detrimental to gut health ... Our findings suggest that the HPD altered the colonic microbial community, shifted the metabolic profile, and affected the host response in the colons of rats toward an increased risk of colonic disease"
• The Effect of Protein-Enriched Meal Replacement on Waist Circumference Reduction among Overweight and Obese Chinese with Hyperlipidemia - J Am Coll Nutr. 2015 Dec 9:1-9 - "Eligible patients were randomized 1:1 to a high-protein (HP) diet (2.2 g protein/kg/day) or a standard-protein (SP) diet (1.1 g protein/kg/ day) provided twice daily for 3 months ... Although mean weight loss and percent BMI reduction were greater with HP than SP at 12 weeks, the differences were not significant. There was, however, a significantly greater decrease in waist-hip ratio with HP versus SP (-0.03 ± 0.03 vs. -0.01 ± 0.04; p < 0.05)"
• Protein Supplementation at Breakfast and Lunch for 24 Weeks beyond Habitual Intakes Increases Whole-Body Lean Tissue Mass in Healthy Older Adults - J Nutr. 2015 Nov 18 - "lean tissue mass (LTM) ... 60 healthy older men and women (aged 61 ± 5 y) with a body mass index (in kg/m2) of 25.8 ± 3.6 consumed either 0.165 g/kg body mass of a milk-based protein matrix (PRO) or an isoenergetic, nonnitrogenous maltodextrin control (CON) at breakfast and midday meals, the lower protein-containing meals of the day, for 24 wk ... LTM increased by 0.45 (95% CI: 0.06, 0.83) kg in the PRO group compared with a decrease of 0.16 (95% CI: -0.49, 0.17) kg in the CON group (P = 0.006). Appendicular LTM accounted for the majority of the difference in LTM, increasing by 0.27 (95% CI: 0.05, 0.48) kg in the PRO group compared with no change in the CON group"
• Dietary Protein Intake Is Protective Against Loss of Grip Strength Among Older Adults in the Framingham Offspring Cohort - J Gerontol A Biol Sci Med Sci. 2015 Nov 2 - "Greater protein intake, regardless of source, was associated with less decrease in grip strength (all p for trend ≤.05): participants in the lowest quartiles lost 0.17% to 0.27% per year while those in the highest quartiles gained 0.52% to 0.60% per year. In analyses stratified by age, participants aged 60 years or older (n = 646) had similar linear trends on loss of grip strength for total and animal (all p for trend <.03) but not plant protein, while the trends in participants younger than 60 years (n = 896) were not statistically significant"
• A high protein diet (3.4 g/kg/d) combined with a heavy resistance training program improves body composition in healthy trained men and women - a follow-up investigation - J Int Soc Sports Nutr. 2015 Oct 20;12:39 - "Consuming a high protein diet (3.4 g/kg/d) in conjunction with a heavy resistance-training program may confer benefits with regards to body composition. Furthermore, there is no evidence that consuming a high protein diet has any deleterious effects"
• The effects of beef protein isolate and whey protein isolate supplementation on lean mass and strength in resistance trained individuals - a double blind, placebo controlled study - J Int Soc Sports Nutr. 2015; 12 - "Thirty college-aged, resistance-trained males and females were randomly assigned to one of three treatment groups. Subjects consumed two servings (46g) of Beef Protein Isolate (BeefISO™), Whey Protein isolate or maltodextrin. Subjects trained 5 days per week (3 resistance training, 2 cardio) for 8 weeks as a part of a daily undulating periodized resistance-training program. Two servings of protein were consumed immediately following exercise or at a similar time of day on off days ... Both beef protein isolate (↑5.7%) and whey protein isolate (↑4.7%) each lead to a significant increase in lean body mass compared with baseline (p < 0.0001). Fat loss was also significantly decreased at 8 weeks compared to baseline for beef protein isolate and whey, 10.8% and 8.3% respectively" - [Nutra USA]
• High dietary protein decreases fat deposition induced by high-fat and high-sucrose diet in rats - Br J Nutr. 2015 Aug 19 - "high-sucrose (HS) ... high-protein diets reduced by 20 % the adiposity gain induced by HS and high-sucrose high-fat (HS-HF) diets"
• Higher Total Protein Intake and Change in Total Protein Intake Affect Body Composition but Not Metabolic Syndrome Indexes in Middle-Aged Overweight and Obese Adults Who Performed Resistance and Aerobic Exercise for 36 Weeks - J Nutr. 2015 Aug 5 - "body composition (BC) ... total protein intake (TPro) ... In conjunction with exercise training, higher TPro promoted positive changes in BC but not in MetS indexes in overweight and obese middle-aged adults. Changes in TPro from before to during the intervention also influenced BC responses and should be considered in future research when different TPro is achieved via diet or supplements"
• Higher Protein Intake Is Associated with Higher Lean Mass and Quadriceps Muscle Strength in Adult Men and Women - J Nutr. 2015 May 27 - "total protein (TP), animal protein (AP), and plant protein (PP) intake ... In men and women, leg lean mass was higher in participants in the highest quartile of TP and AP intake compared with those in the lowest quartiles of intake [least squares means (kg): TP-17.6 vs. 17.1 in men, P-trend: 0.005, and 11.7 vs. 11.4 in women, P-trend: 0.006; AP-17.6 vs. 17.1 in men, P-trend: 0.002, and 11.7 vs. 11.4 in women, P-trend: 0.003]. PP intake was not associated with lean mass in either sex. In men and women, quadriceps strength was higher in participants in the highest quartile of PP intake compared with those in the lowest quartile [least squares means (kg): 22.9 vs. 21.7 in men, P-trend: 0.01, and 19.0 vs. 18.2 in women, P-trend: 0.01]; this association was no longer significant after adjustment for fruit and vegetable intake (P-trend: 0.06 in men and 0.10 in women). Although no significant association was observed for AP intake in either sex, nonsignificant protective trends were observed for TP intake (P-trend: 0.08 in men and 0.10 in women)"
• Effective translation of current dietary guidance: understanding and communicating the concepts of minimal and optimal levels of dietary protein - Am J Clin Nutr. 2015 Apr 29 - "The protein content of diets for adults can be based on the Recommended Dietary Allowance (RDA) of 0.80 g/kg per day ... The Acceptable Macronutrient Distribution Range (AMDR) reflects the interrelation between the macronutrients and affords dietitians and clinicians additional flexibility in diet planning. Accounting for the caloric value of RDAs for carbohydrate and fat, "flexible calories" emerge as an opportunity to create varied eating plans that provide for protein intakes in excess of the RDA but within the AMDR. Protein Summit 2.0 highlighted the growing body of scientific evidence documenting the benefits of higher protein intakes at amounts approximating twice the RDA, which include promotion of healthy body weight and preservation of lean body mass and functional ability with age"
• Protein and healthy aging - Am J Clin Nutr. 2015 Apr 29 - "The potential benefits of young and middle-aged adults adopting a diet pattern whereby adequate protein is consumed at each meal as a countermeasure to sarcopenia are presented and discussed. For example, meeting a protein threshold (~25-30 g/meal) represents a promising, yet still largely unexplored dietary strategy to help maintain muscle mass and function. For many older adults, breakfast is a carbohydrate-dominated lower-protein meal and represents an opportunity to improve and more evenly distribute daily protein intake. Although both animal and plant-based proteins can provide the required essential amino acids for health, animal proteins generally have a higher proportion of the amino acid leucine. Leucine plays a key role in stimulating translation initiation and muscle protein anabolism and is the focus of ongoing research. Protein requirements should be assessed in the light of habitual physical activity. An evenly distributed protein diet provides a framework that allows older adults to benefit from the synergistic anabolic effect of protein and physical activity" - Note:  I put a scoop of leucine into an empty jelly jar with about a third cup of water and shake it then swill it every morning just before breakfast.  It's probably the worst thing you'll ever taste but I'm convinced it works for preserving muscles  See Leucine products at Amazon.com.
• Higher-Protein Diets Are Associated with Higher HDL Cholesterol and Lower BMI and Waist Circumference in US Adults - J Nutr. 2015 Mar;145(3):605-14 - "Americans of all body weights typically consume protein in excess of the RDA. Higher-protein diets are associated with lower BMI and waist circumference and higher HDL cholesterol compared to protein intakes at RDA levels. Our data suggest that Americans who consume dietary protein between 1.0 and 1.5 g/kg BW potentially have a lower risk of developing cardiometabolic disease"
• Low-carbohydrate diets and cardiovascular and total mortality in Japanese: a 29-year follow-up of NIPPON DATA80 - Br J Nutr. 2014 Sep;112(6):916-24 - "low-carbohydrate diets (LCD) ... The multivariable-adjusted hazard ratio (HR) for CVD mortality using the Cox model comparing the highest v. lowest deciles of LCD score was 0.60 (95 % CI 0.38, 0.94; P trend= 0.021) for women and 0.78 (95 % CI 0.58, 1.05; P trend= 0.079) for women and men combined; the HR for total mortality was 0.74 (95 % CI 0.57, 0.95; P trend= 0.029) for women and 0.87 (95 % CI 0.74, 1.02; P trend= 0.090) for women and men combined. None of the associations was statistically significant in men"
• Diets Higher in Protein Predict Lower High Blood Pressure Risk in Framingham Offspring Study Adults - Am J Hypertens. 2014 Sep 6 - "high BP (HBP) ... Higher protein intakes were associated with lower mean SBP and DBP. Both animal and plant proteins lowered BP and led to statistically significant reductions in HBP risk (hazard ratios of 0.68 and 0.51, respectively). Participants in the highest tertile of total protein intake had 40% less risk (95% confidence interval [CI], 0.45-0.78) of developing HBP. Beneficial effects of protein were apparent for men and women and for normal-weight and overweight individuals. Higher protein diets also characterized by higher fiber intakes led to a 59% reduction (95% CI, 0.37-0.66) in HBP risk"
• Animal Protein Intake Is Associated with Higher-Level Functional Capacity in Elderly Adults: The Ohasama Study - J Am Geriatr Soc. 2014 Feb 27 - "Participants were divided into quartiles according to intake levels of total, animal, and plant protein ... men in the highest quartile of animal protein intake had significantly lower risk of higher-level functional decline than those in the lowest quartile (odds ratio (OR) = 0.41, 95% confidence interval (CI) = 0.20-0.83; P for trend .01). These associations were not seen in women (OR = 0.76, 95% CI = 0.41-1.34; P for trend .37)"
• Dietary Protein Distribution Positively Influences 24-h Muscle Protein Synthesis in Healthy Adults - J Nutr. 2014 Jan 29 - "The consumption of a moderate amount of protein at each meal stimulated 24-h muscle protein synthesis more effectively than skewing protein intake toward the evening meal"
• Effect of resistance-type exercise training with or without protein supplementation on cognitive functioning in frail and pre-frail elderly: secondary analysis of a randomized, double-blind, placebo-controlled trial - Mech Ageing Dev. 2013 Dec 26 - "Physical activity has been proposed as one of the most effective strategies to prevent cognitive decline. Protein supplementation may exert an additive effect. The effect of resistance-type exercise training with or without protein supplementation on cognitive functioning in frail and pre-frail elderly people was assessed in a secondary analysis. Two 24-week, double-blind, randomized, placebo-controlled intervention studies were carried out in parallel. Subjects performed a resistance-type exercise program of two sessions per week (n=62) or no exercise program (n=65). In both studies subjects were randomly allocated to either a protein (2×15g daily) or a placebo drink ... In frail and pre-frail elderly resistance-type exercise training in combination with protein supplementation improved information processing speed (changes in domain score 0.08±0.51 versus -0.23±0.19 in the non-exercise group, p=0.04). Exercise training without protein supplementation was beneficial for attention and working memory (changes in domain scores 0.35±0.70 versus -0.12±0.69 in the non-exercise group, p=0.02)" - See protein drinks at Amazon.com.
• High protein intake is associated with low prevalence of frailty among old Japanese women: a multicenter cross-sectional study - Nutr J. 2013 Dec 19;12(1):164 - "A total of 2108 grandmothers or acquaintances of dietetic students aged 65 years and older participated in this cross-sectional multicenter study, which was conducted in 85 dietetic schools in 35 prefectures of Japan. Intakes of total, animal, and plant protein and eight selected amino acids were estimated from a validated brief-type self-administered diet history questionnaire and amino acid composition database ... Adjusted ORs (95% CI) for frailty in the first, second, third, fourth, and fifth quintiles of total protein intake were 1.00 (reference), 1.02 (0.72, 1.45), 0.64 (0.45, 0.93), 0.62 (0.43, 0.90), and 0.66 (0.46, 0.96), respectively (P for trend = 0.001). Subjects categorized to the third, fourth, and fifth quintiles of total protein intake (>69.8 g/d) showed significantly lower ORs than those to the first quintile"
• Dietary protein and muscle in older persons - Curr Opin Clin Nutr Metab Care. 2014 Jan;17(1):5-11 - "Results from muscle protein anabolism, appetite regulation and satiety research support the contention that meeting a protein threshold (approximately 30g/meal) represents a promising strategy for middle-aged and older adults concerned with maintaining muscle mass while controlling body fat"
• Dietary protein and plasma total homocysteine, cysteine concentrations in coronary angiographic subjects - Nutr J. 2013 Nov 7;12(1):144 - "High animal-protein diet was positively associated with high tHcy concentrations, whereas high plant-protein diet was inversely associated with tHcy concentrations. Furthermore the total protein intake was strongly related to tCys concentrations"
• Association of total protein intake with bone mineral density and bone loss in men and women from the Framingham Offspring Study - Public Health Nutr. 2013 Oct 29:1-7 - "This suggests that greater protein intake benefits women especially those with lower Ca intakes. However, protein effects are not significant for short-term changes in bone density. Contrastingly, in men, higher protein intakes lead to greater bone loss at the trochanter"
• Higher-protein diet for weight management in young overweight women: a 12 month randomised controlled trial - Diabetes Obes Metab. 2012 Dec 26 - "This randomised controlled trial compared the efficacy of two iso-energetically restricted (5600kJ) diets (HP: 32% protein, 41% carbohydrate, 25% fat or HC: 20, 58, 21% respectively) in 71 (HP:n=36; HC:n=35) young healthy women (18-25y; BMI≥27.5kg/m(2) ) for weight (kg; percent weight loss), body composition, metabolic and iron changes assessed at baseline, six and 12 months ... No significant between-diet differences were observed at 12 months. Biochemistry remained within normal ranges with HP showing superior preservation of ferritin at six months (HP:53(40-66); HC:46(30-61)µg/L; p=0.029). Both diets supported clinically meaningful weight loss with HP tending to be more effective in the medium-term"
• Effect of a High-Protein Diet on Kidney Function in Healthy Adults: Results From the OmniHeart Trial - Am J Kidney Dis. 2012 Dec 4 - "Participants were fed each of 3 diets for 6 weeks. Feeding periods were separated by a 2- to 4-week washout period. Weight was held constant on each diet. The 3 diets emphasized carbohydrate, protein, or unsaturated fat; dietary protein was either 15% (carbohydrate and unsaturated fat diets) or 25% (protein diet) of energy intake ... Compared with the carbohydrate and unsaturated fat diets, the protein diet increased cystatin C-based eGFR by ~ 4 mL/min/1.73 m(2) (P < 0.001) ... A healthy diet rich in protein increased eGFR. Whether long-term consumption of a high-protein diet leads to kidney disease is uncertain"
• Treatment of Metabolic syndrome by combination of physical activity and diet needs an optimal protein intake: a randomized controlled trial - Nutr J. 2012 Sep 17;11(1):72 - "During the treatment based on restricted diet and exercise in senior people with metabolic syndrome, the lower threshold intake for protein must be set at 1.2 g/kg/day to maintain blood protein homeostasis" - Note:  160 pounds is 72.5 kilograms which would be 87 grams of protein per day.
• Effects of higher- versus lower-protein diets on health outcomes: a systematic review and meta-analysis - Eur J Clin Nutr. 2012 Apr 18 - "Higher-protein diets probably improve adiposity, blood pressure and triglyceride levels, but these effects are small and need to be weighed against the potential for harms"
• A diet with 35 % of energy from protein leads to kidney damage in female Sprague-Dawley rats - Br J Nutr. 2011 May 3:1-8 - "High-protein (HP) diets for weight loss remain popular despite questions surrounding overall safety. In a recent study using the pig model, we showed that long-term intakes from whole proteins at 35 % energy (en %) cause moderate renal histological damage. To examine whether this observation may be species specific or more generalisable, the effect of this diet in rats was examined ... Rats consuming the HP diet had 17 % higher kidney weights (P < 0.0001), three times higher proteinuria (P < 0.0001) and 27 % higher creatinine clearance (P = 0.0012) compared with those consuming the NP diet. Consistent with this, HP-fed rats had larger glomeruli (P < 0.0001) and more glomerulosclerosis (P = 0.0003) compared with NP-fed rats. The HP diet also resulted in altered levels of free monocyte chemoattractant protein-1 (P < 0.0001). The histological changes are consistent with those observed in the pig model. In contrast to the pig model, the elevated proteinuria and creatinine clearance observed in the rat model are also usually observed with HP consumption in human subjects. These results indicate that the rat is a useful model for HP effects on the kidney and, along with previous results using the pig model, suggest that long-term intake of high levels of protein may be detrimental to renal health"
• A protein-rich beverage consumed as a breakfast meal leads to weaker appetitive and dietary responses v. a protein-rich solid breakfast meal in adolescents - Br J Nutr. 2011 Feb 15:1-5 - "A total of fifteen adolescents (eight girls and seven boys; age 14 (sem 1) years, BMI percentile 79 (sem 4) %) randomly completed two testing days that included protein-rich (PR) breakfast meals (38 % of energy as protein, 48 (sem 2) g/meal) provided as a solid (S) or beverage (B). Breakfast was 24 % of estimated daily energy needs (2146 (sem 96) kJ/meal). Perceived appetite and satiety responses were collected over 5 h followed by an ad libitum lunch buffet. The PR-S meal led to greater reductions in 4 h postprandial appetite ( - 6221 (sem 1171) mm × 240 min) v. the PR-B meal ( - 3570 (sem 957) mm × 240 min; P < 0.05). When examining the data according to hourly responses, the PR-S meal led to greater reductions in appetite during postprandial hours 2, 3 and 4 v. the PR-B meal (all comparisons, P < 0.05). No differences in postprandial hourly or total (4 h) fullness were observed following the PR-S v. PR-B meals. The PR-S meal led to approximately 480 kJ less energy consumed at the ad libitum lunch buffet (1418 (sem 222) kJ) v. the PR-B meal (1900 (sem 326) kJ; P < 0.05). These data indicate that, although the food form of the PR breakfast meals had little, if any, effect on satiety, the appetitive responses were diminished and the subsequent food intake was greater when protein was consumed as a beverage v. a solid meal"
• Dietary protein and risk of ischemic heart disease in middle-aged men - Am J Clin Nutr. 2010 Sep 29 - "The RR of IHD was 1.08 (95% CI: 0.95, 1.23; P for trend = 0.30) comparing the top with the bottom quintile of percentage of energy from total protein. RRs for animal and vegetable protein were 1.11 (95% CI: 0.97, 1.28; P for trend = 0.18) and 0.93 (95% CI: 0.78, 1.12; P for trend = 0.49), respectively. When the population was restricted to "healthy" men (those free of hypertension, hypercholesterolemia, and diabetes at baseline), the RR of IHD was 1.21 (95% CI: 1.01, 1.44; P for trend = 0.02) for total protein, 1.25 (95% CI: 1.04, 1.51; P for trend = 0.02) for animal protein, and 0.93 (95% CI: 0.72, 1.19; P for trend = 0.65) for vegetable protein ... We observed no association between dietary protein and risk of total IHD in this group of men aged 40-75 y. However, higher intake of animal protein may be associated with an increased risk of IHD in "healthy" men"
• Acid diet (high-meat protein) effects on calcium metabolism and bone health - Curr Opin Clin Nutr Metab Care. 2010 Aug 16 - "Increased potential renal acid load resulting from a high protein (intake above the current Recommended Dietary Allowance of 0.8 g protein/kg body weight) intake has been closely associated with increased urinary calcium excretion. However, recent findings do not support the assumption that bone is lost to provide the extra calcium found in urine. Neither whole body calcium balance is, nor are bone status indicators, negatively affected by the increased acid load. Contrary to the supposed detrimental effect of protein, the majority of epidemiological studies have shown that long-term high-protein intake increases bone mineral density and reduces bone fracture incidence. The beneficial effects of protein such as increasing intestinal calcium absorption and circulating IGF-I whereas lowering serum parathyroid hormone sufficiently offset any negative effects of the acid load of protein on bone health"
• Major Dietary Protein Sources and Risk of Coronary Heart Disease in Women - Circulation. 2010 Aug 16 - "26 years of follow-up ... higher intakes of red meat, red meat excluding processed meat, and high-fat dairy were significantly associated with elevated risk of CHD. Higher intakes of poultry, fish, and nuts were significantly associated with lower risk. In a model controlling statistically for energy intake, 1 serving per day of nuts was associated with a 30% (95% confidence interval, 17% to 42%) lower risk of CHD compared with 1 serving per day of red meat. Similarly, compared with 1 serving per day of red meat, a lower risk was associated with 1 serving per day of low-fat dairy (13%; 95% confidence interval, 6% to 19%), poultry (19%; 95% confidence interval, 3% to 33%), and fish (24%; 95% confidence interval, 6% to 39%). Conclusions-These data suggest that high red meat intake increases risk of CHD and that CHD risk may be reduced importantly by shifting sources of protein in the US diet"
• Long-Term High Intake of Whole Proteins Results in Renal Damage in Pigs - J Nutr. 2010 Jul 28 - "These findings suggest that long-term intakes of protein at the upper limit of the AMDR from whole protein sources may compromise renal health"
• Intake of plant foods and associated nutrients in prostate cancer risk - Nutr Cancer. 2009;61(2):216-24 - "Plant foods and associated nutrients may impact prostate cancer (PC) risk and survival ... Reduced PC risk was associated with the highest tertile of cryptoxanthin (OR = 0.51; 95% CI = 0.35-0.75), fiber (OR = 0.56; 95% CI = 0.35-0.89), vitamin C (OR = 0.60; 95% CI = 0.41-0.88), and fruits and/or fruit juices (OR = 0.46; 95% CI = 0.31-0.68), with significant linear trends. Increased risk of PC was associated with the highest tertile of protein (OR = 1.99; 95% CI = 1.05-3.79) and daily servings of grains (OR = 1.99; 95% CI = 1.23-3.22) with significant linear trends"
• Inadequate dietary protein increases hunger and desire to eat in younger and older men - J Nutr. 2007 Jun;137(6):1478-82 - "younger and older men who consume inadequate protein experience appetite changes that may promote increased food intake"
• Effect of high protein vs high carbohydrate intake on insulin sensitivity, body weight, hemoglobin A1c, and blood pressure in patients with type 2 diabetes mellitus - J Am Diet Assoc. 2005 Apr;105(4):573-80 - "Both the high-carbohydrate and high-protein groups lost weight (-2.2+/-0.9 kg, -2.5+/-1.6 kg, respectively, P <.05) and the difference between the groups was not significant ( P =.9). In the high-carbohydrate group, hemoglobin A1c decreased (from 8.2% to 6.9%, P <.03), fasting plasma glucose decreased (from 8.8 to 7.2 mmol/L, P <.02), and insulin sensitivity increased (from 12.8 to 17.2 mumol/kg/min, P <.03). No significant changes in these parameters occurred in the high-protein group, instead systolic and diastolic blood pressures decreased (-10.5+/-2.3 mm Hg, P =.003 and -18+/-9.0 mm Hg, P <.05, respectively)"
• The impact of dietary protein on calcium absorption and kinetic measures of bone turnover in women - J Clin Endocrinol Metab. 2004 Nov 16 - "The high protein diet caused a significant reduction in the fraction of urinary calcium of bone origin and a nonsignificant trend toward a reduction in the rate of bone resorption. There were no protein induced effects on net bone balance. These data directly demonstrate that, at least in the short-term, high protein diets are not detrimental to bone"
• High-protein, low-fat diets are effective for weight loss and favorably alter biomarkers in healthy adults - J Nutr. 2004 Mar;134(3):586-91 - "low-fat, energy-restricted diets of varying protein content (15 or 30% energy) promoted healthful weight loss, but diet satisfaction was greater in those consuming the high-protein diet"
• Dietary protein intake and urinary excretion of calcium: a cross-sectional study in a healthy Japanese population - Am J Clin Nutr 1998 Mar;67(3):438-444 - "Our findings suggest that excess protein, especially that rich in sulfur-containing amino acids, in habitual diets may augment calcium excretion in the urine, at least in the elderly."