A High-Protein Diet With Resistance Exercise Training Improves Weight Loss and Body Composition in Overweight and Obese Patients With Type 2 Diabetes

OBJECTIVE - To evaluate the effects of two low-fat hypocaloric diets differing in the carbohydrate-to-protein ratio, with and without resistance exercise training (RT), on weight loss, body composition, and cardiovascular disease (CVD) risk outcomes in overweight/obese patients with type 2 diabetes. RESEARCH DESIGN AND METHODS - A total of 83 men and women with type 2 diabetes (aged 56.1±7.5 years, BMI 35.4±4.6 kg/m²) were randomly assigned to an isocaloric, energy-restricted diet (female subjects 6 MJ/day, male subjects 7 MJ/day) of either standard carbohydrate (CON; carbohydrate:protein:fat 53:19:26) or high protein (HP; 43:33:22), with or without supervised RT (3 days/week) for 16 weeks. Body weight and composition, waist circumference (WC), and cardiometabolic risk markers were assessed. RESULTS - Fifty-nine participants completed the study. There was a significant group effect (P ≤ 0.04) for body weight, fat mass, and WC with the greatest reductions occuring in HP+RT (weight [CON: -8.6 ± 4.6 kg, HP: -9.0 ± 4.8 kg, CON+RT: -10.5 ± 5.1 kg, HP+RT: -13.8 ± 6.0 kg], fat mass [CON: -6.4 ± 3.4 kg, HP: -6.7 ± 4.0 kg, CON+RT: -7.9 ± 3.7 kg, HP+RT: -11.1±3.7 kg], and WC[CON: -8.2±4.6 cm, HP: -8.9±3.9 cm, CON+RT: -11.3 ± 4.6 cm, HP+RT: -13.7 ± 4.6 cm]). There was an overall reduction (P < 0.001) in fat-free mass (-2.0 ± 2.3 kg), blood pressure (-15/8 ± 10/6 mmHg), glucose (-2.1 ± 2.2 mmol/l), insulin (-4.7 ± 5.4 mU/l), A1C (-1.25 ± 0.94%), triglycerides (-0.47 ± 0.81 mmol/l), total cholesterol (-0.67±0.69 mmol/l), and LDL cholesterol (-0.37±0.53 mmol/l), with no difference between groups (P ≥ 0.17). CONCLUSIONS - An energy-restricted HP diet combined with RT achieved greater weight loss and more favorable changes in body composition. All treatments had similar improvements in glycemic control and CVD risk markers.