title: Sex differences in energy homeostatis following a diet relatively high in protein exchanged with carbohydrate, assessed in a respiration chamber in humans.
abstract: BACKGROUND
  Obesity prevalence is generally higher in women than in men, and a paucity of research with sex-specific approaches exists. The question arises whether current weight loss programmes, largely developed and tested on women, are appropriate for men.
  
  
  OBJECTIVE
  Investigate 24 h energy metabolism, satiety and related hormones during a diet relatively high in protein (HP), exchanged with carbohydrate compared to an adequate-protein (AP) diet, in a respiration chamber in men, in comparison with previous outcomes in women.
  
  
  METHODS
  Ten healthy males (BMI: 22.5+/-1.6 kg/m(2), age: 25+/-3.5 y) were fed in energy balance with an AP (10/60/30% of energy of protein/carbohydrate/fat) or a HP (30/40/30% of energy of protein/carbohydrate/fat) diet in a randomized cross-over design.
  
  
  RESULTS
  During the HP diet, 24 h Energy Expenditure (10.5+/-0.5 vs 10.0+/-0.5 MJ/d; p<0.05), Sleeping Energy Expenditure (7.1+/-0.3 vs 6.9+/-0.2 MJ/d; p<0.05), protein balance (0.5+/-0.02 vs 0.0+/-0.01 MJ/d; p<0.05), satiety (AUC) p<0.05, and plasma GLP-1 concentrations (42+/-23 vs 28+/-16 AUC; p<0.005) were significantly higher and 24 h RQ (0.80 vs 0.85; p<0.01), fat balance (-0.85+/-0.03 vs 0.05 vs 0.03 MJ/d; p<0.01) and hunger (AUC) p<0.05, were significantly lower. Comparisons reveal a stronger reaction in men in energy expenditure and substrate oxidation, whereas satiety reacted stronger in the women.
  
  
  CONCLUSIONS
  Effects of a diet relatively high in protein exchanged with carbohydrate, vs an adequate protein diet are a stronger increased energy expenditure, fat oxidation, protein anabolism in men, and a stronger increased satiety in women, thereby creating sex-specific conditions for long-term use for body-weight management.
authors.affiliation: Department of Human Biology, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands. m.westerterp@hb.unimaas.nl
authors.forename: Margriet S
authors.initials: MS
authors.lastname: Westerterp-Plantenga
authors.forename: Manuela P G M
authors.initials: MP
authors.lastname: Lejeune
authors.forename: Astrid J P G
authors.initials: AJ
authors.lastname: Smeets
authors.forename: Natalie D
authors.initials: ND
authors.lastname: Luscombe-Marsh