Effect on Body Weight of Replacing Dietary Fat with Olestra for Two or Ten Weeks in Healthy Men and Women

To examine in two separate studies the effects of replacing dietary fat with Olestra on body composition and weight change in healthy young men and women.Ten healthy, lean young men participated in Study One that was a 22-day single blind, within-subject design. After a control diet (40% fat) for eight days Study One subjects received an Olestra-substituted diet (31% metabolizable fat) for 14 days. Study Two was a randomized parallel-arm clinical trial with 15 healthy, lean and overweight young women. These subjects were randomly assigned to receive a control diet (40% fat), an Olestra-containing diet (31% metabolizable fat) or a reduced-fat diet (31% fat) for 10 weeks. All foods were provided to the subjects, and energy intakes were not restricted. The primary endpoint in both studies was change from baseline in body weight. In Study Two, body composition was measured by dual energy x-ray absorptiometry. In both studies, food intake and nutrient compensation were assessed.In Study One fat substitution by Olestra resulted in a significant 1.7 kg weight loss from baseline. In Study Two, change in body weight and body fat from baseline were statistically significant in all groups, but the group with Olestra lost significantly more weight from baseline (-5.0 kg) than the other two groups. In Study One there was partial compensation for the decreased energy intake, while in Study Two, compensation was seen only for those on the reduced-fat diet.Replacement of 1/3 of dietary fat with Olestra in periods of up to 10 weeks results in weight loss in men and women.