Effects of two energy-restricted diets differing in the carbohydrate/protein ratio on weight loss and oxidative changes of obese men

Int J Food Sci Nutr. 2009;60 Suppl 3:1-13. doi: 10.1080/09637480802232625. Epub 2009 Jul 24.


Introduction: Low-carbohydrate, high-protein diets are a current challenge in the nutritional treatment of obesity.

Objective: To compare the effect of a low-carbohydrate high-protein diet with a traditional hypocaloric diet on weight loss and mitochondrial oxidative metabolism.

Subjects and methods: Nineteen obese men (age 36+/-6 years; body mass index 34+/-2 kg/m2) were randomized to follow one of the two diets-control diet (15% protein; 30% lipids; 55% carbohydrates) or high-protein diet (30% protein; 30% lipids; 40% carbohydrates)-over an 8-week period. Anthropometry, biochemical variables, resting energy expenditure and mitochondrial oxidation were measured at the start and at the end of the intervention.

Results: The high-protein diet produced a greater weight loss (-8.3+/-1.2% versus -5.5+/-2.5%, P = 0.012) than the control diet. Interestingly, an activation in the mitochondrial oxidation was found in the high-protein-fed group. This stimulation was positively correlated with the final resting energy expenditure and negatively associated with the final fat mass content.

Conclusion: Low-carbohydrate high-protein diets could involve specific changes in mitochondrial oxidation that could be related to a higher weight loss.

Publication types

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

MeSH terms

  • Adult
  • Diet, Carbohydrate-Restricted*
  • Diet, Reducing*
  • Dietary Carbohydrates / pharmacology*
  • Dietary Proteins / pharmacology*
  • Energy Intake*
  • Humans
  • Male
  • Mitochondria / drug effects
  • Mitochondria / metabolism
  • Obesity / diet therapy*
  • Obesity / metabolism
  • Oxidation-Reduction
  • Weight Loss / drug effects*
  • Weight Loss / physiology


  • Dietary Carbohydrates
  • Dietary Proteins