The third sensitivity analysis indicated that compared with the BMI category ‘normal weight + overweight’, there was an indirect effect of CRP on the association between obesity and elevated somatic symptoms (indirect effect: β = 0.003, 95% CI: 0.001, 0.007) (Supplementary Table S6 and Fig. S2). The gene discussed is CRP; the disease is obesity due to melanocortin 4 receptor deficiency.