The Effects of Supervised Exercise Training on Weight Control and Other Metabolic Outcomes in Patients With Type 2 Diabetes: A Meta-Analysis

Few studies have investigated the dose-response relationship between exercise and weight control. This study aimed to assess the effects of different types of supervised exercise training on weight control and other metabolic outcomes in patients with type 2 diabetes mellitus and explore the dose-response relationship between exercise volume/duration and these outcomes. PubMed/ MEDLINE, Embase, and Cochrane databases were searched for studies between January 1980 and June 2019. Randomized control trials in type 2 diabetes mellitus patients with supervised exercise training versus control treatment were included. The primary outcome was changes in body weight (kg). The secondary outcomes included changes in waist circumference (cm) and total body fat percentage (%). Forty-two randomized control trials, including 3,625 patients with type 2 diabetes mellitus were included. Overall, exercise treatment was associated with significant reduction in body weight (weighted mean differences, -1.10 kg; 95% CI [-1.58, -0.62], p < .01), waist circumference (weighted mean differences, -2.51 cm; 95% CI [-3.25, -1.77], p < .01), and total body fat (weighted mean differences, -1.16%; 95% CI [-1.58%, -0.75%], p < .01). The percentage of total body fat was reduced by all types of exercise, with a significant difference between aerobic exercise and resistance exercise (p = .02) and a significant difference between combined exercise and resistance exercise (p < .01). A higher volume of aerobic exercise and a higher volume of resistance exercise were superior in reducing body weight. In conclusion, supervised exercise training improved metabolic outcomes in general, while different types and volume of exercises have their own merits.