People assigned to eat diets with a different composition of protein (15% vs 25%), fat (20% vs 40%) and carbohydrates (35% to 65%), but the same number of calories, lost the same amount of weight and same amount of fat according to a recent study from researchers at Harvard University. The average weight loss was 13.9 lbs after six months which was similar in all the diet groups, with 9.2 lbs coming from body fat, and 4.6 lbs coming from lean body mass (muscle) “with no differences between 25% and 15% protein, 40% and 20% fat, or 65% and 35% carbohydrate.”

Here is a 7-minute video of obesity researcher, George Bray, MD, talking about the results of their new study in which they overfed subjects roughly an extra 1,000 calories per day of either a low-protein diet (5% protein), a normal-protein diet (15% protein), or a high-protein diet (25% protein), and the effect that this had on body weight and body fat.

All groups gained weight. The normal- and high-protein groups gained the most weight (13-14 lbs vs 7 lbs for the low-protein group), and all groups gained roughly the same amount of body fat.

In other words, overeating caused weight gain regardless of weather they were overeating a high-protein diet or a low-protein diet.

Even though the low-protein group gained weight, they lost a small amount of lean body mass (muscle).

Dr. Bray notes that this shows that not eating enough protein—a diet containing only 5% protein—will not prevent loss of lean body mass. He notes that this finding was unexpected.

“Our findings provide conclusive proof that European Neandertals… lived on a diet of mainly hunted animal meat,” said Fred H. Smith, anthropologist from Northern Illinois University in DeKalb, Illinois.

A high-protein, reduced-fat diet causes more weight loss and more belly fat loss than a moderate-protein reduced-fat diet according to the always interesting research group from Denmark which includes Arnie Astrup and S. Toubro.

People lost twice as much weight after three months and six months on a high-protein, low-carb diet than a low-fat, high-carbohydrate diet, but the difference in weight loss was not significantly different after one year according to the first randomized, controlled trial of a low-carb diet that was published in The New England Journal of Medicine.

“Participants on a low-carbohydrate diet had more favorable overall outcomes at one-year than did those on a conventional [low-fat] diet,” concludes a new study conducted at the Philadelphia Veterans Affairs Medical Center. People who were assigned to follow a low-carb diet maintained a weight loss of 11.2 pounds after one-year compared to a weight loss of 6.8 pounds for people who were assigned to follow a low-fat diet. The difference in weight loss between the groups was not statistically significant, however there still was an 80 percent chance that this difference in weight loss was due to the diet. Some articles have concluded that this study shows that low-carb diets are no better than low-fat diets, however this was not the conclusion of the study.

Women lose twice as much weight—18.7 lbs vs 8.6 lbs—and twice as much body fat—10.6 lbs vs 4.4 lbs—on a low-carbohydrate diet as a low-fat diet according to a recent study.

Patients eating a low-carbohydrate group lost nearly twice as much weight as those in the low-fat group. Those in the low-carb group lost an average of 26.4 pounds versus 14.3 pounds for those in the low-fat group.

Adolescent lost 21.8 pounds in three months on a low-carbohydrate diet compared to 10.8 pounds on a low-fat diet according to a recent study.

Increasing protein intake to 25 percent of calories increases both fat loss and weight loss according to one study where 65 obese patients ate a low-fat diet (30 percent fat) which contained either 12 percent protein or 25 percent protein.

Whenever and wherever possible, our hunter-gather ancestors ate 45-65 percent of their calories as animal food and the remaining 35-55 percent as plant foods according to a recent paper from researchers at Colorado State University.

Our hunter-gather ancestors showed little signs of cardiovascular disease despite eating a diet containing about 65 percent of their calories from animal food and 35 percent from plant foods, containing 28-58 percent fat according to a paper from researchers at Colorado State University.

For years, one of the arguments given against high-protein diets was that they would cause a loss of bone mass. However, this is not true according to a recent study from Denmark.

In the past, another concern about high-protein was that they would cause kidney problems. This is not so according to a recent study.

Low-carbohydrate diets cause the body to release fat from fat cells which are converted to ketone bodies. These ketone bodies have three important functions according to a recent paper about low-carbohydrate diets.

Low carbohydrate diets cause weight loss because of decreased calorie intake, not because of reduced carbohydrate content according to a recent review of low-carb diets.

A high-soy-protein, low-fat diet causes more weight loss than lifestyle education according to a study from Germany.

Although “dietary compliance [after one-year] was poor in all groups, women maintain more of their weight loss with a high-protein, low-carbohydrate diet than a high-fat, low-carbohydrate diet or a low-fat, high-carbohydrate, high-fiber diet according to a recent study from researchers at the Edgar National Centre for Diabetes Research in Dunedin, New Zealand.

Women instructed to eat either a high-protein, low-carbohydrate diet or a high-fat, low-carbohydrate diet lost more weight than those who were instructed to eat a high-carbohydrate, low-fat diet according to a recent study from researchers at the Edgar National Centre for Diabetes Research in Dunedin, New Zealand. “This study provides strong support for the use of higher protein diets as an alternative to the conventional [high-carbohydrate, low-fat] approach,” the researchers concluded.

Women lost more weight during the first six months when instructed to eat a high-fat, low-carbohydrate diet (18.7 pounds or 8.7 percent of their body weight) or a high-protein, low-carbohydrate diet (17.6 lbs or 8.5 percent) compared to a high-carbohydrate, low-fat diet (13 pounds or 6 percent of their body weight) according to a recent study from researchers at the Edgar National Centre for Diabetes Research in Dunedin, New Zealand, but those in the high-fat group gained back more body fat (5.1 pounds) than those in the high-protein group, who gained back 2 pounds of body fat, or those in the high-carbohydrate group who gained back 1.8 pounds of body fat.

More women who were instructed to follow a high-protein diet returned after one year for a follow-up (93 percent) than those who were instructed to follow a high-fat, low-carbohydrate diet (77 percent) or those who were instructed to follow a high-carbohydrate, low-fat diet (75%) according to a recent study. This suggests that people may find it easier and more effective to follow instructions to eat a high-protein diet than a high-fat or high-carbohydrate diet.

After losing about 20 lbs on a very-low calorie liquid diet, people instructed to eat a high-protein diet lost an additional 2.4 lbs in 3 months compared to a weight gain of 2.6 lbs for those instructed to eat a high-carbohydrate diet.

This was a difference of about 5 lbs.

People assigned to eat a diet containing 25% protein and 30% fat lost more weight and more fat than a group assigned to eat a diet containing 15% protein and 30% fat.

High-protein diets suppress appetite in adults, however, this does not appear to be the case in children or adolescents according to a NEW study from researchers at Leeds Metropolitan University in Leeds, UK.

This is the third time they have found this.

They also note that other studies have also found that high-protein diets fail to suppress appetite in obese children.

Men eat less and lose more weight on a high-protein, low-carbohydrate diet than a high-protein, medium-carbohydrate diet according to a new study from researchers at the Division of Obesity and Metabolic Health at the Rowett Research Institute in Aberdeen, Scotland.

Those fed a diet containing 30 percent protein and only 4 percent carbohydrates ate 9 percent fewer calories without any dietary restrictions—3035 calories per day versus 3328—and lost more weight during the one-month study—13.9 pounds versus 10 pounds.