Defining metabolically healthy obesity in children: a scoping review

We conducted a scoping review to identify definitions of metabolically healthy obesity (MHO), describe gaps in the literature, and establish a universal definition of MHO in children. We searched electronic databases from January 1980 to June 2017 and grey literature. Experimental, quasi-experimental, or observational studies were eligible for inclusion if they (i) included a definition of MHO that identified risk factors, cut-off values, and the number of criteria used to define MHO, and (ii) classified 2-18 year olds as overweight or obese. Two reviewers independently screened 1,711 papers for relevance and quality; we extracted data from 39 individual reports that met inclusion criteria. Most (31/39; 79%) definitions of MHO included an absence of cardiometabolic risk factors. Heterogeneity across MHO definitions, obesity criteria, and sample sizes/characteristics resulted in variable prevalence estimates (3-80%). Finally, we convened an international panel of 46 experts to complete a 4-round Delphi process to generate a consensus-based definition of MHO. Based on consensus (≥ 80% agreement), our definition of MHO included: high density lipoprotein-cholesterol > 40 mg/dl (or > 1.03 mmol/l), triglycerides ≤ 150 mg/dl (or ≤ 1.7 mmol/l), systolic and diastolic blood pressure ≤ 90th percentile, and a measure of glycemia. This definition of MHO holds potential universal value to enable comparisons between studies and inform clinical decision-making for children with obesity.