Fluoxetine's effect on weight loss in obese subjects

Forty-five obese subjects with a mean weight of 102.9 kg and a body mass index (in kg/m2) of 37.6 were randomly assigned to a fluoxetine-diet group (n = 23) or a placebo-diet group (n = 22) for 52 wk. At week 29, 14 subjects on fluoxetine who completed the study attained their maximum weight loss of 12.4 kg, an amount significantly greater than the maximum weight loss of 4.5 kg for the 16 on placebo who completed the study. The fluoxetine group's significantly greater mean weight loss continued through week 45. However, those on fluoxetine regained a mean of 4.2 kg from their lowest weight (P less than 0.001) whereas the placebo group did not. By the end of the study, each group weighed significantly less than they did at baseline (fluoxetine: -8.2 kg; placebo: -4.5 kg; P less than 0.05) although the difference between groups was no longer significant (P greater than 0.05). Several factors were considered as possible causes for the regain with fluoxetine.