BMI-predictive proteins included established obesity markers and obesity-related proteins, including adiponectin, CRP, IGFBP1, IGFBP2, PRG4, SHBG, apolipoproteins (APOA4, APOF) and inflammatory response proteins (A2M, APCS, LBP, HSPG2, HP, AOC3, ITGB1, VNN1). Here, IGFBP1 is linked to obesity due to melanocortin 4 receptor deficiency.