Aims: We examined the effects of physical activity with or without dietary restriction for 3 months on regional fat and insulin sensitivity and compared the effect of total energy expenditure from all levels of physical activity with that of physical activity energy expenditure from moderate-to-vigorous exercise in obese women with Type 2 diabetes.
Methods: In this randomized, controlled trial, we assessed change of body weight, abdominal visceral fat area, subcutaneous fat area and insulin sensitivity, expressed as K(ITT), and monitored total energy expenditure and physical activity energy expenditure using an accelerometer during a 12-week intervention in four groups: control, diet, exercise and diet plus exercise.
Results: The mean body mass index was 28.0 +/- 2.7 kg/m(2) and the mean duration of diabetes was 8 +/- 6 years. Both the diet and diet plus exercise groups showed significant body weight loss compared with the control group (P < 0.05). However, the visceral fat area was reduced only in the diet and exercise group (P = 0.017) and the subcutaneous fat area was reduced only in the diet group (P = 0.009). Mean energy intake was an independent determinant of the change in subcutaneous fat area (P = 0.020) and mean total anergy expenditure was an independent determinant of visceral fat area (P = 0.002). Insulin sensitivity K(ITT) was associated with physical activity energy expenditure (P = 0.006), energy intake (P = 0.047) and the change in fructosamine level (P = 0.016) but not with changes in body weight, subcutaneous fat area, visceral fat area or adipokine level.
Conclusions: Exercise had an additive effect to dietary restriction on visceral fat reduction. Visceral fat area was associated with total energy expenditure, but insulin sensitivity was associated with physical activity energy expenditure.