Effects of sex on the change in visceral, subcutaneous adipose tissue and skeletal muscle in response to weight loss

OBJECTIVE: To examine the influence of sex on whole body and regional subcu taneous, visceral, total adipose tissue (AT), skeletal muscle (SM), and lea n tissue in response to weight loss induced by diet alone (DO) or the combi nation of diet and aerobic (DA) or resistance exercise (DR). DESIGN: Sixty upper-body obese men and women were randomly assigned to one of three treatments: DO, DA, or DR. All tissues were measured using a whole body, magnetic resonance imaging protocol. RESULTS: Within each group reductions were observed for body weight (simila r to 11 kg), subcutaneous and visceral AT (P < 0.01). After controlling for pretreatment differences in tissue size, reductions in total adiposity, to tal and regional subcutaneous and Visceral adipose tissue were not differen t between sexes (P > 0.1). Independent of sex, the reduction in visceral AT was greater than subcutaneous AT (P < 0.05) in response to DO and DA. With the exception of DA women, the reduction in abdominal subcutaneous AT was greater (P < 0.05) than lower-body subcutaneous AT in response to diet and exercise, but not diet alone, in bath sexes (P > 0.05). Independent of sex, skeletal muscle mass was preserved within the exercise groups (P > 0.05) b ut not diet alone (P < 0.05). Peak VO2 (l/min) improved in the DA groups as did muscular strength in the DR groups (P < 0.01). CONCLUSIONS: These findings indicate that in response to diet or diet and e xercise-induced weight loss, reductions in total adiposity, subcutaneous an d visceral adipose tissue distribution are not different in obese men and w omen. Independent of sex, the combination of diet and exercise results in a preservation of skeletal muscle mass, a preferential reduction of abdomina l subcutaneous AT, and improved functional capacity by comparison to diet a lone.