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 subcutaneous, visceral, total adipose tissue (AT), skeletal muscle (SM), and lean tissue in response to weight loss induced by diet alone (DO) or the combination of diet and aerobic (DA) or resistance exercise (DR).


METHODS
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 ( approximately 11 kg), subcutaneous and visceral AT (P<0.01). After controlling for pretreatment differences in tissue size, reductions in total adiposity, total and regional subcutaneous and visceral adipose tissue were not different 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 both sexes (P>0.05). Independent of sex, skeletal muscle mass was preserved within the exercise groups (P>0.05) but 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 exercise-induced weight loss, reductions in total adiposity, subcutaneous and visceral adipose tissue distribution are not different in obese men and women. Independent of sex, the combination of diet and exercise results in a preservation of skeletal muscle mass, a preferential reduction of abdominal subcutaneous AT, and improved functional capacity by comparison to diet alone.
Janssen
I
I
School of Physical and Health Education, Queen's University, Kingston, Ontario, Canada.
Ross
R
R
D000273:Adipose Tissue; D000368:Aged; D001823:Body Composition; D004038:Diet, Reducing; D004734:Energy Metabolism; D015444:Exercise; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal; D009765:Obesity / Q000503:physiopathology / Q000628:therapy*; D010101:Oxygen Consumption; D012727:Sex Characteristics; D014891:Weight Lifting; D015431:Weight Loss