Reduction in Obesity and Related Comorbid Conditions after Diet-Induced Weight Loss or Exercise-Induced Weight Loss in Men: A Randomized, Controlled Trial
Published on Jul 18, 2000in Annals of Internal Medicine19.32
· DOI :10.7326/0003-4819-133-2-200007180-00008
Background: The independent effects of diet- or exercise-induced weight loss on the reduction of obesity and related comorbid conditions are not known. The effects of exercise without weight loss on fat distribution and other risk factors are also unclear. Objective: To determine the effects of equivalent diet- or exercise-induced weight loss and exercise without weight loss on subcutaneous fat, visceral fat, skeletal muscle mass, and insulin sensitivity in obese men. Design Randomized, controlled trial. Setting: University research center. Participants: 52 obese men (mean body mass index [±SD], 31.3 ± 2.0 kg/m 2 ) with a mean waist circumference of 110.1 ± 5.8 cm. Intervention: Participants were randomly assigned to one of four study groups (diet-induced weight loss, exercise-induced weight loss, exercise without weight loss, and control) and were observed for 3 months. Measurements: Change in total, subcutaneous, and visceral fat; skeletal muscle mass; cardiovascular fitness; glucose tolerance and insulin sensitivity. Results: Body weight decreased by 7.5 kg (8%) in both weight loss groups and did not change in the exercise without weight loss and control groups. Compared with controls, cardiovascular fitness (peak oxygen uptake) in the exercise groups improved by approximately 16% (P 0.2). However, these values were significantly greater than those in the control and exercise without weight loss groups (P < 0.001). Conclusions: Weight loss induced by increased daily physical activity without caloric restriction substantially reduces obesity (particularly abdominal obesity) and insulin resistance in men. Exercise without weight loss reduces abdominal fat and prevents further weight gain.