X-PERT: weight reduction with orlistat in obese subjects receiving a mildly or moderately reduced-energy diet: early response to treatment predicts weight maintenance.

AIM

To determine the effect of two different levels of energy deficit on weight loss in obese patients treated with orlistat.

METHODS

Patients (n=430) were randomized in a 1-year, multicentre, open-label, parallel group study conducted at 23 hospital centres and university medical departments worldwide. Obese outpatients (body mass index 30--43 kg/m(2)) aged 18--70 years with a body weight of >or=90 kg and a waist circumference of >or=88 cm (women) or >or=102 cm (men) were treated with orlistat 120 mg three times daily plus a diet that provided an energy deficit of either 500 or 1,000 kcal/day for 1 year. Orlistat treatment was discontinued in patients who did not achieve >or=5% weight loss after assessment at 3 and 6 months. The primary outcome measure was change in body weight from baseline at week 52.

RESULTS

Reported mean difference in energy intake between the two groups (500-1,000 kcal/day deficit) at weeks 24 and 52 was actually 111 and 95 kcal/day respectively. Of the 430 patients involved in the study, 295 achieved >or=5% weight loss at both 3 and 6 months. In this population, at week 52, weight loss from baseline was similar for patients randomized to either the 500 or the 1,000 kcal/day deficit diet (-11.4 kg vs. -11.8 kg, respectively; p=0.778). After 12 months of treatment with orlistat, 84% (n=118/141) and 85% (n=131/154) of patients in the 500 and 1,000 kcal/day deficit groups, respectively, achieved >or=5% weight loss, and 50% (n=70/141) and 53% (n=82/154) of patients, respectively, achieved >or=10% weight loss. Patients in both the diet treatment groups showed similar significant improvements in blood pressure, lipid levels and waist circumference at week 52.

CONCLUSIONS

Treatment with orlistat was associated with a clinically beneficial weight loss, irrespective of the prescribed dietary energy restriction (-500 or -1000 kcal/day). Patients who achieved >or=5% weight loss at 3 months achieved long-term, clinically beneficial weight loss with orlistat plus either diet. Therefore, identifying patients who lose at least 5% weight after 3 months and who maintain this weight loss up to 6 months is a valuable treatment algorithm to select patients who will benefit most from orlistat treatment in combination with diet.