BACKGROUND
This systematic review and meta-analysis evaluates the additional effects 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 glycemic 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 (0.06 % [95% CI 0.25; 0.13]), 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 addition of exercise to hypocaloric diet.

CONCLUSION
Additional effects of exercise to hypocaloric diet in adults with overweight or obesity and type 2 diabetes were not shown for body weight, body composition, or glycaemic control, while cardio-respiratory fitness improves.