OBJECTIVE: To study the effect on weight loss in obese subjects by replacement of carbohydrate by protein in ad libitum consumed fat-reduced diets. DESIGN: Randomized dietary intervention study over six months comparing two ad libitum fat reduced diets (30% of total energy) strictly controlled in composition: High-carbohydrate (HC, protein 12% of total energy) or high-protein (HP, protein 25% of total energy). SETTING AND PARTICIPANTS: Subjects were 65 healthy, overweight and obese subjects (50 women, 15 men, aged 18 ± 55 y) randomly assigned to HC (n 25), HP (n 25) or a control group (C, n 15). All food was provided by selfselection in a shop at the department, and compliance to the diet composition was evaluated by urinary nitrogen excretion. MAIN OUTCOME MEASURE: Change in body weight, body composition and blood lipids. RESULTS: More than 90% completed the trial. Weight loss after six months was 5.1 kg in the HC group and 8.9 kg in the HP group (difference 3.7 kg, 95% con®dence interval (CI)(1.3 ± 6.2 kg) P`0.001), and fat loss was 4.3 kg and 7.6 kg, respectively (difference 3.3 kg (1.1 ± 5.5 kg) P`0.0001), whereas no changes occurred in the control group. More subjects lost b10 kg in the HP group (35 %) than in the HC group (9 %). The HP diet only decreased fasting plasma triglycerides and free fatty acids signi®cantly. CONCLUSIONS: Replacement of some dietary carbohydrate by protein in an ad libitum fat-reduced diet, improves weight loss and increases the proportion of subjects achieving a clinically relevant weight loss. More freedom to choose between protein-rich and complex carbohydrate-rich foods may allow obese subjects to choose more lean meat and dairy products, and hence improve adherence to low-fat diets in weight reduction programs.

BACKGROUND:We have previously reported that a fat-reduced high-protein diet had more favourable effects on body weight loss over 6 months than a medium-protein diet. OBJECTIVE: To extend this observation by a further 6-12 months less stringent intervention and a 24 months follow-up. DESIGN: A randomised 6 months strictly controlled dietary intervention followed by 6-12 months dietary counselling period, and a subsequent 24 months follow-up, comparing an ad libitum, fat-reduced diet (30% of energy) either high in protein (25% of energy, HP) or medium in protein (12% of energy, MP). SUBJECTS: A total of 50 overweight and obese subjects (age: 19-55 y; BMI: 26-34 kg/m 2 ). MEASUREMENTS: Change in body weight, body composition and blood parameters. RESULTS: After 6 months, the HP group (n ¼ 23) achieved a greater weight loss than the MP group (n ¼ 23) (9.4 vs 5.9 kg) (Po0.01). After 12 months, 8% had dropped out in the HP vs 28% in the MP group (Po0.07). After 12 months, the weight loss was not significantly greater among the subjects in the HP group (6.2 and 4.3 kg), but they had a 10% greater reduction in intraabdominal adipose tissue and more in the HP group (17%) lost 410 kg than in the MP (Po0.09). At 24 months, both groups tended to maintain their 12 months weight loss, but more than 50% were lost to follow-up. CONCLUSION: A fat-reduced diet high in protein seems to enhance weight loss and provide a better long-term maintenance of reduced intra-abdominal fat stores.

Dietary carbohydrate/protein ratio has no effect on inflammatory markers, but the study confirmed that body fatness is positively associated with levels of serum CRP.

The present study examined the hypothesis that patients with apparent diet-resistant obesity have subnormal energy expenditure. Ten biochemically euthyroid patients (eight women and two men), aged 21-76 years, with either excessive gynoid fat distribution or obesity (BMI 23.8-41.0), were referred to the department thought to be suffering from a low metabolic rate syndrome since dietary records showed very low energy intake (< 5 MJ day-1) in combination with failure to lose weight on low-energy diets. Twenty-four-hour energy expenditure (24-h EE), basal energy expenditure (BEE) and sleeping energy expenditure (SEE) were measured in a respiration chamber on a fixed activity programme. The patients consumed a diet containing 37 energy-per cent (E%) fat, 47 E% carbohydrate and 16 E% protein. The individual energy intake was estimated from a previously established algorithm between 24-h EE and fat-free mass (FFM) estimated by bioimpedance. Results were compared with equivalent values in a reference population of 76 subjects ranging from normal weight to obese. No evidence of low metabolism was found in terms of adjusted 24-h EE in the patients with diet resistance when compared with the control group (9263 +/- 819 kJ vs. 9211 +/- 558 kJ). No differences were found when comparing adjusted BEE and SEE in the two groups (7655 +/- 727 vs. 7411 +/- 770 kJ 24 h-1 and 7048 +/- 672 vs. 6911 +/- 408 kJ 24 h-1). The physical activity index (PAI) during the chamber stay was likewise within normal values (1.32 +/- 0.07 vs. 1.34 +/- 0.04; NS).