Variations in the prevalence and predictors of prevalent metabolically healthy obesity in adolescents.

BACKGROUND: Obesity is a heterogeneous condition, which includes a subset of individuals that can be classified as having metabolically healthy obesity (MHO), but there is no consensus on what constitutes MHO. Thus, the objective of the study is to examine the prevalence and predictors of prevalent MHO in adolescents using various definitions of MHO.

METHODS: Cross-sectional data from the 1999-2010 National Health and Nutrition Examination Surveys were used. Participants included 316 male and 316 female adolescents aged 12-19 years with a BMI ≥ 95th percentile. Two definitions were used to define MHO. First, MHO was defined as having ≤1 metabolic syndrome criteria (excluding waist) and being free of type 2 diabetes, hypertension and dyslipidemia. Second, MHO was defined as being free of all metabolic syndrome criteria, insulin resistance and inflammation.

RESULTS: The prevalence of MHO was 42% (male) and 74% (female) using the first definition and 7% (male) and 12% (female) using the second more conservative definition. Lower abdominal obesity (waist circumference) and lower insulin resistance predicted prevalent MHO in male and female adolescents for both definitions (p < 0.01). Associations between dietary components and MHO were weak and inconsistent, while physical activity and inflammation were not associated with MHO in male and female adolescents for both definitions (p > 0.05).

CONCLUSIONS: The prevalence of MHO in adolescents varied across definitions, with lower levels of abdominal obesity and insulin resistance as the most consistent predictors of prevalent MHO status.