Effect of a high-protein energy-restricted diet combined with resistance training on metabolic profile in older individuals with metabolic impairments

Adequate protein intake and resistance training are effective strategies to maintain muscle mass, but the effect of their combination on metabolic profile during weight loss remains to be determined in older adults. The main objective of this study was to determine the effect of a 16-week high-protein caloric restriction combined with resistance training on chronic disease risk factors in obese older individuals with metabolic impairments. A total of 26 overweight adults aged between 60 and 75 years (BMI 32.4 ± 3.9 kg/m²) with at least 2 factors of the metabolic syndrome participated in this study and were randomized into two groups: 1) high-protein caloric restriction (HP; n= 12) and 2) high-protein caloric restriction combined with dynamic-resistance training (HP+RT; n=14). Caloric intake was reduced by 500 kcal/d in all participants and protein intake equated 25-30% of total calories (~1.4 g/kg/d). Exercise training consisted of 3 session/week of resistance training on pulley machines. Outcome measures included total and trunk fat mass (FM), total and appendicular lean body mass (LBM), fasting glucose level, lipid profile and blood pressure. Our results showed that total and trunk FM (all p<0.0001) as well as fasting glucose (p<0.0001), triglycerides (p=0.002) and total cholesterol (p=0.03) levels decreased similarly in both groups. However, total (p=0.04) and appendicular (p=0.02) LBM decreased in the HP group only. Our data show that high-protein energy restriction improves health profile of obese elderly at high risk of chronic disease but needs to be combined with resistance training to maintain LBM.