Recently I commented on a study that suggested calories matter most when it comes to weight loss. That may be true, but another new study has shown that a diet moderately high in protein is superior for fat loss and other health markers. Here are some bullet points from the Journal of Nutrition study.

Study Details

  • Researchers followed the weight-loss efforts of 130 persons during 4 months of active weight loss and 8 months of maintenance.
  • group followed a moderate-protein diet (40% carbohydrates, 30% protein, 30% fat) while the other followed a diet based on USDA's food-guide pyramid (55% carbohydrates, 15% protein, 15% fat).
  • Participants met every week for weigh-ins and nutrition instruction. participants were taught how to follow their diet, how to grocery shop, and how to prepare the meals.
  • They also measured everything they ate three days a week


  • Although the amount of weight lost in both groups was similar, at 4 months participants in the protein group had lost 22 percent more body fat than members of the food-pyramid group. At 12 months, the moderate-protein dieters had lost 38 percent more body fat.
  • Although at 4 months the food-guide pyramid appeared to be more effective in lowering LDL and total cholesterol levels, at 12 months LDL levels came back up until both diets were equally effective
  • The moderate-protein diet had by far the bigger effect on lowering triglycerides, and that lasted as long as individuals remained on the diet, according to lead researcher Dr. Layman.
Of the two types of lipid problems, high triglycerides pose a greater risk for heart disease. Approximately twice as many people have high triglycerides, and people with this condition are approximately four times more likely to die from heart disease, - Donald Layman
  • The protein diet was easier to follow and maintain long-term, with 64 percent of the moderate-protein dieters completing the study compared to 45 percent of dieters using the high-carbohydrate diet, Layman said.
  • Average weight loss for the protein group was 23 percent higher than the food-pyramid group, with 31 percent of completers in the protein group losing more of than 10 percent of their initial body weight versus 21 percent of the food-pyramid group.


  • This study certainly makes sense and got me thinking about the concept of required vs. optimal. The USDA guidelines may provide enough protein for the average person but it would appear that these recommendations are not optimal for most poeple.
  • One theory as to why people didn't lose much fat in the previous study comparing different macronutrient ratios was that protein intake was curiously low in all groups.
  • This study parallels previous studies that have shown moderately high protein intake is superior for fat loss. (Appl Physiol Nutr Metab. Dec. 2006)
  • Other studies have also shown that when protein is constant, higher carb intake isn't overly relevant. (Am J Clin Nutr;82: 41-48 July, 2005). This study also demonstrated the moderately high protein intake group consumed 441 calories less per day than the standard protein group.
  • Last note - try not to get too wrapped up in looking at macronutrients like protein as a percentage of calories but rather according to your body weight. 1g per pound of body weight is the commonly accepted amount for fat loss and performance.

Source: Science Daily