Significant features of basal and maximal energy expenditure parameters in obese adults

Abstract

Aim: To compare body composition, resting metabolic rate, and maximal aerobic capacity parameters in obese adults and healthy controls, as well as to investigate the associations among these parameters. Materials and methods: A total of 120 participants, 60 obese participants (30 male, 30 female) with body mass indexes (BMIs) over 30 kg/m(2) and 60 healthy controls (30 male, 30 female) with BMIs of 18-25 kg/m(2), were included in the study. BMI was calculated as body weight divided by the square of the height (kg/m2). Body fat percentage, total body fat, and lean body mass were established with bioelectric impedance analysis. Resting metabolic rates (RMRs) were determined with indirect calorimeter. Maximal aerobic capacity was estimated with the Astrand exercise protocol. Results: RMRs (kcal/day) were significantly higher in male and female obese individuals than in the controls. VO2 max (L/min) levels were not significantly different between obese and control individuals of either sex. However, RMR per kilogram of body weight and VO2 max expressed in milliliters per kilogram of body weight were significantly lower in male and female obese adults compared to the controls. BMI, body fat percentage, and total body fat were positively correlated with RMR (kcal/day), but negatively correlated with RMR [(kcal/day)/kg] and VO2 max (mL/kg/min) in both sexes. Conclusion: We suggest that resting and maximal energy expenditure per kilogram of body weight are impaired in obese adults. Both low resting metabolic rate and weak maximal aerobic capacity are related to excess body fat in obese subjects.