Eat A High-Protein Diet to Lose Fat and Preserve Muscle: Why and How Protein Works

Posted: 22/07/2012 in English, Science and stuff

written by Charles Poliquin

Eat a high-protein diet to lose fat and preserve muscle. A new study in the journal Nutrition and Metabolism is one of the first to consider the mechanism behind the magic of high-protein diets for fat loss.

The study compared the effect of two energy-restricted diets on weight loss. Women ate 1,700 calories a day and men ate 1,900 calories a day with the following macronutrient breakdown: A high-protein diet (1.6 g/kg of body weight/day with a near equal ratio of macronutrients), or a low-protein diet (0.8 g/kg of body weight/day with roughly 15 percent protein, 55 percent carb, and 30 percent fat).

Results showed that after one year, the high-protein diet produced much greater fat loss in both men and women than the low-protein diet. Both diets resulted in a similar amount of weight lost in both genders, about 10 percent of baseline bodyweight, but the high-protein diet preserved lean mass to a much greater degree, and the weight that was lost was almost entirely from fat.

Interestingly, more of the total weight loss was derived from fat relative to muscle mass in men, with 77 percent of weight loss coming from fat in the high-protein diet group and only 67 percent coming from fat among the women on the high-protein diet. In the low-protein group, 63 percent of the lost weight was from fat for men, and 57 percent of the lost weight was from fat for women.

Obviously, greater higher protein diets produce much better body composition results, and with strength training, lean mass could be better preserved. That greater lean mass is lost in women reinforces the need for women to build muscle if they want to sustain weight loss. Additionally, researchers point to a protein threshold dose to lose the most fat and maintain muscle during weight loss—at least 1.5 g/kg of body weight a day is necessary to avoid the breakdown of lean tissue. Another study found that for every additional 0.1 g/kg of protein intake, 0.62 kg of lean mass was preserved on a weight loss diet.

Higher dietary protein produces greater fat loss for various reasons. First, there’s the greater thermogenesis or energy required to breakdown dietary protein, which raises the resting metabolic significantly. Second, there’s the fact that if protein makes up a smaller percentage of total energy, carb intake will be increased, which can lead to persistently high insulin and lack of fat loss.

Finally, A higher dietary protein intake has been shown to trigger muscle protein synthesis so that lean mass is preserved and fat is used for fuel. Protein synthesis also increases energy expenditure, raising the metabolic rate, leading to fat loss. A high intake of the branched-chain amino acids, particularly leucine, appears to produce the best fat loss/muscle maintenance results.

The research group in this study had hoped to find that the different macronutrient content of the two diets would influence where the participants lost fat—from the trunk or the gluteofemoral (glutes and thighs) region. This was not the case, but the results did show that men lost more trunk fat and women lost more femoral fat, which is likely due to different hormones between the genders. The researchers didn’t elaborate on how the endocrine system influences body composition, but if you’d like to learn more about this topic, please consider attending one of my BioSignature Courses because I go into how the hormones can be rebalanced by manipulating nutrition and supplementation.




  1. diet pills says:

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  2. Dewayne Gaffer says:

    Some people turn to higher-protein diets to lose weight. That’s because some researchers suggest that higher-protein diets help people better control their appetites and calorie intake.Diets with 30% protein are now being considered “reasonable” and the term “high protein diet” is now reserved for diets with over 50% protein…

    My very own blog site

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