BMI, measured or self-reported weight in kg per height in metres squared (Supplementary Tables 1 and 3) was adjusted for age, age squared, and any necessary study-specific covariates (for example, genotype-derived principal components) in a linear regression model. The resulting residuals were transformed to approximate normality using inverse normal scores. For studies with no known related individuals, residuals were calculated separately by sex and case/control status. For family-based studies, residuals were calculated with men and women together, adding sex as an additional covariate in the linear regression model. Relatedness was accounted for in a study-specific manner (Supplementary Table 2).
