Aims: This systematic review and meta-analysis evaluates the additional effect of exercise to hypocaloric diet on body weight, body composition, glycaemic control and cardio-respiratory fitness in adults with overweight or obesity and type 2 diabetes.
Methods: Embase, Medline, Web of Science and Cochrane Central databases were evaluated, and 11 studies were included. Random-effects meta-analysis was performed on body weight and measures of body composition and glycaemic control, to compare the effect of hypocaloric diet plus exercise with hypocaloric diet alone.
Results: Exercise interventions consisted of walking or jogging, cycle ergometer training, football training or resistance training and duration varied from 2 to 52 weeks. Body weight and measures of body composition and glycaemic control decreased during both the combined intervention and hypocaloric diet alone. Mean difference in change of body weight (-0.77 kg [95% CI: -2.03; 0.50]), BMI (-0.34 kg/m2 [95% CI: -0.73; 0.05]), waist circumference (-1.42 cm [95% CI: -3.84; 1.00]), fat-free mass (-0.18 kg [95% CI: -0.52; 0.17]), fat mass (-1.61 kg [95% CI: -4.42; 1.19]), fasting glucose (+0.14 mmol/L [95% CI: -0.02; 0.30]), HbA1c (-1 mmol/mol [95% CI: -3; 1], -0.1% [95% CI: -0.2; 0.1]) and HOMA-IR (+0.01 [95% CI: -0.40; 0.42]) was not statistically different between the combined intervention and hypocaloric diet alone. Two studies reported VO2max and showed significant increases upon the addition of exercise to hypocaloric diet.
Conclusions: Based on limited data, we did not find additional effects of exercise to hypocaloric diet in adults with overweight or obesity and type 2 diabetes on body weight, body composition or glycaemic control, while cardio-respiratory fitness improved.
Keywords: body composition; caloric restriction; exercise; glycaemic control; type 2 diabetes; weight loss.
© 2023 The Authors. Diabetic Medicine published by John Wiley & Sons Ltd on behalf of Diabetes UK.