Comparison of Muscle Mass Indexes According to Protein Intake in Obese Patients

Abstract

Background: Protein is the most important nutrient for the muscle synthesis and maintenance of muscle mass. However, there have been no studies comparing muscle mass indexes according to protein intake in obese patients. Thus, the present study investigated the hypothesis that high protein intake positively affected muscle mass indexes in obese patients. Methods: Male (n=50) and female (n=30) obese patients were recruited. Each sex was divided into 2 groups according to their protein intake. Dietary intake, fat-free mass, appendicular skeletal muscle mass, appendicular skeletal muscle mass/height2, skeletal muscle index, total bone area, bone mineral count, bone mineral density, total cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol, interleukin-6, tumor necrosis factor α, smoking, alcohol, and exercise were assessed. Results: Fat-free mass, appendicular skeletal muscle mass, and appendicular skeletal muscle mass/height2 were significantly higher in obese men in the higher protein intake group, while serum triglyceride was significantly lower in the same group. However, bone indexes and inflammatory cytokines according to protein intake were not significantly different in obese men. Fat-free mass, bone indexes, muscle indexes, blood lipid profiles, and inflammatory cytokines were not significantly different according to protein intake in obese women. Conclusion: In this population, increasing protein intake may positively affect fat-free mass, appendicular skeletal muscle mass, appendicular skeletal muscle mass/height2, and serum triglyceride in obese men. Therefore, additional studies may be necessary to identify the appropriate level of protein intake required to prevent a decrease in muscle mass, and increase muscle mass in obese patients.