Association Between Body Composition and Obesity Phenotypes in Children and Adolescents

Assessment of influencing factors is critical for the management of different obesity phenotypes among children and adolescents. We investigated the association between body composition and metabolically unhealthy phenotypes independently or in an interaction with physical activity or sleep, among 7572 children and adolescents with normal weight or overweight/obesity from Guangzhou, China. High body fat percentage (BF%), trunk-to-limb fat ratio (T/L), waist-to-height ratio (WHtR), low soft lean mass percentage (SLM%), and appendicular skeletal muscle percentage (ASM%) were all associated with increased risk of metabolically unhealthy overweight/obesity (MUO) (odds ratios ranging from 1.31 to 1.52). High T/L and WHtR were associated with 66% and 93% increased metabolically unhealthy normal weight (MUNW) risk. Relative excess risk due to an interaction >0 further indicated positive interactions between insufficient physical activity and high BF%, WHtR, or low SLM on MUO and MUNW. An interaction was also found between insufficient sleep and high T/L or low SLM% on MUNW. Excess total and central fat increases MUO risk, while adequate muscle mass reduces the risk. Central fat is also positively associated with MUNW risk. Sufficient physical activity and sleep can mitigate the detrimental effects of adiposity and boost the protection of muscle against obesity phenotypes.