Effect of orlistat treatment on body composition and resting energy expenditure during a two-year weight-reduction programme in obese Finns

OBJECTIVE: To examine the effect of orlistat (Xenical(TM)) treatment on bod y composition and resting energy expenditure (REE) during a 2 y weight-redu ction programme in obese Finns. SUBJECTS: Of initially 96 obese subjects who participated in the weight-red uction programme, those 72 subjects (13 men, 59 women, body mass index (BMI ) 35.9+/-3.9 kg/m(2), age 43.4+/-6.0 y, mean+/-s.d.) with the complete set of data for 2 y were included in the study. DESIGN: After a 4-week lead-in period, subjects were randomized with either orlistat 120 mg t.i.d. or placebo t.i.d. in conjunction with a mildly hypo energetic balanced diet for 1 y. This was followed by ly double-blind perio d with the subjects within each treatment group re-assigned to receive orli stat 120 mg t.i.d. or placebo t.i.d. in conjunction with a weight maintenan ce diet. MEASUREMENTS: Body composition and REE were measured after an overnight fas t by a bioelectrical impedance method and indirect calorimeter, respectivel y. The measurements were performed at the beginning and at 3, 6, 12 and 24 months. RESULTS: During the first year, the orlistat-treated group had greater redu ction of body weight and fat mass but not of fat-free mass or REE as compar ed to placebo. During the second year, orlistat treatment was associated wi th smaller regain of body weight and fat mass with no significant differenc es in the changes of fat-free mass or REE as compared to placebo. CONCLUSION: In addition to better weight loss and maintenance of reduced we ight, orlistat treatment is associated with beneficial changes in body comp osition but with no excess decrease in resting energy expenditure as compar ed to that achieved during placebo with a dietary therapy alone.