Effect of a high-protein, energy-restricted diet on body composition, glycemic control, and lipid concentrations in overweight and obese hyperinsulinemic men and women

Am J Clin Nutr. 2003 Jul;78(1):31-9. doi: 10.1093/ajcn/78.1.31.


Background: It is not clear whether varying the protein-to-carbohydrate ratio of weight-loss diets benefits body composition or metabolism.

Objective: The objective was to compare the effects of 2 weight-loss diets differing in protein-to-carbohydrate ratio on body composition, glucose and lipid metabolism, and markers of bone turnover.

Design: A parallel design included either a high-protein diet of meat, poultry, and dairy foods (HP diet: 27% of energy as protein, 44% as carbohydrate, and 29% as fat) or a standard-protein diet low in those foods (SP diet: 16% of energy as protein, 57% as carbohydrate, and 27% as fat) during 12 wk of energy restriction (6-6.3 MJ/d) and 4 wk of energy balance ( approximately 8.2 MJ/d). Fifty-seven overweight volunteers with fasting insulin concentrations > 12 mU/L completed the study.

Results: Weight loss (7.9 +/- 0.5 kg) and total fat loss (6.9 +/- 0.4 kg) did not differ between diet groups. In women, total lean mass was significantly (P = 0.02) better preserved with the HP diet (-0.1 +/- 0.3 kg) than with the SP diet (-1.5 +/- 0.3 kg). Those fed the HP diet had significantly (P < 0.03) less glycemic response at weeks 0 and 16 than did those fed the SP diet. After weight loss, the glycemic response decreased significantly (P < 0.05) more in the HP diet group. The reduction in serum triacylglycerol concentrations was significantly (P < 0.05) greater in the HP diet group (23%) than in the SP diet group (10%). Markers of bone turnover, calcium excretion, and systolic blood pressure were unchanged.

Conclusion: Replacing carbohydrate with protein from meat, poultry, and dairy foods has beneficial metabolic effects and no adverse effects on markers of bone turnover or calcium excretion.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blood Glucose / analysis*
  • Body Composition*
  • Cholesterol, HDL / blood
  • Cholesterol, LDL / blood
  • Diet
  • Dietary Proteins / administration & dosage*
  • Energy Intake*
  • Fatty Acids, Nonesterified / blood
  • Female
  • Humans
  • Hyperinsulinism / complications*
  • Insulin Resistance
  • Lipids / blood*
  • Male
  • Middle Aged
  • Obesity / complications
  • Obesity / physiopathology*
  • Triglycerides / blood


  • Blood Glucose
  • Cholesterol, HDL
  • Cholesterol, LDL
  • Dietary Proteins
  • Fatty Acids, Nonesterified
  • Lipids
  • Triglycerides