Resting metabolic rate and its association with body composition parameters in 9- to 18-year-old Indian children and adolescents.

Objectives: Obesity is a disorder of energy balance with increasing prevalence in Indian children. Objectives were to study 1) resting metabolic rate (RMR), anthropometry, body composition (BC), and their relationships in Indian children and adolescents affected with overweight (OW) or obesity (OB) and in non-overweight (NOW) children and 2) factors influencing RMR, such as age, sex, and BC.

Methods: This cross-sectional, observational, multicentric study included 495 children (260 boys) of age 9-18 y who were assessed from six Indian states for sociodemographic and anthropometric parameters using standard protocols. Body composition was assessed by a body impedance analyzer technique (Tanita-BC-420), and RMR was assessed using indirect calorimetry. Data were analyzed using SPSS (version 26) with appropriate statistical tests. The level of significance was set at P < 0.05.

Results: Boys had higher absolute RMR values than did girls (1212±263 kcal/d versus 1066±204 kcal/d; P < 0.001). Weight-adjusted RMR was significantly lower among children classified as OW or OB than among NOW children of both sexes, respectively (P < 0.001). Linear regression analysis revealed fat-free mass, sex, age, and body mass index (BMI) as significant predictors of RMR (P < 0.05).

Conclusions: We found lower weight-adjusted RMR in children classified as OW or OB as compared with NOW children. Our study underlines the importance of low RMR levels among children with a higher BMI, in girls, and with increasing age.