Effect of dietary restraint during and following pegylated recombinant leptin (PEG-OB) treatment of overweight men

OBJECTIVE: To examine the effect of dietary restraint during and following pegylated recombinant leptin (PEG-OB protein) treatment in overweight men. DESIGN: A randomized double-blind placebo-controlled trial in 24 overweight men (BMI: 28.8 +/- 0.3 kg/m(2); age: 34.8 +/- 0.9 y). PEG-OB protein (80 mg) or placebo was administered subcutaneously weekly for 6 weeks, combined with a 2.1 MJ/day energy restriction program. Dietary restraint was determined by the Three-Factor Eating Questionnaire before and after treatment, and after 8 weeks follow-up. RESULTS: During treatment dietary restraint increased, and general hunger, resting energy expenditure and respiratory quotient decreased similarly in the PEG-OB and the placebo group. With PEG-OB treatment, additional weight loss (P < 0.03) was observed. During 8 weeks follow-up, body weight increase was larger in the PEG-OB group compared to placebo (P < 0.05), and body weight regain was faster. Body weight regain was inversely correlated with the increase in cognitive dietary restraint during treatment (PEG-OB group: r(2) = 0.49, P < 0.02; placebo group: r(2) = 0.60, P = 0.01). CONCLUSION: Although treatment with PEG-OB protein led to a greater body weight loss relative to placebo, weight maintenance thereafter was mainly supported by dietary restraint, which was more effective in the placebo-treated group, resulting in a slower regain of body weight.