Exercise-training enhances fat-free mass preservation during diet-induced weight loss: a meta-analytical finding.

A meta-analysis was performed to examine how exercise training and gender influence the composition of diet-induced weight loss. The groups did not differ with respect to either the amount of body weight lost (mean = -10 +/- 1.4 kg) or fat mass lost (mean = -8 +/- 1.1 kg). However, exercise training significantly (P < 0.05) reduced the amount of body weight lost as fat-free mass compared to dietary restriction only (DO) for the same sex. The percentage of weight lost as fat-free mass for diet-plus-exercise (DPE) subjects was approximately half (P < 0.05) of that for DO subjects of the same sex (DO males = 28 +/- 4% of weight lost as fat-free mass; DPE males = 13 +/- 6%, DO females = 24 +/- 2%, DPE females = 11 +/- 3%). These data provide evidence that exercise training reduces the amount of body weight lost as fat-free mass during diet-induced weight loss. In addition, sex differences do not seem to exist with respect to the composition of diet-induced weight loss.