We have used previously-defined criteria for to define overweight, obesity and morbid (class III) obesity6,7; in adults, the thresholds were BMI ≥ 25, 30 and 40 kg.m−2 respectively. In children and adolescents, we used age- and sex-specific percentiles of BMI, calculated from a French reference population27,28, that approximately correspond to these thresholds: overweight and obesity were defined by thresholds at the 90th and 97th percentiles respectively. Childhood morbid obesity was defined as BMI ≥ 4 SDs above the age- and sex-specific mean, which corresponds to a BMI of 40 kg.m−2 between the ages of 20 and 30 years for both men and women; this threshold was used in the recruitment of the SCOOP severe early-onset obesity cohorts7. The age- and sex-specific thresholds use to define obesity and morbid obesity are shown in Figure 1 and Supplementary Figures 1-2. No carriers of a 16p11.2 deletion were reported to be taking atypical antipsychotics (known to be associated with weight gain).
