Significant negative genetic correlation between AN and anthropometric and metabolic traits [including body mass index (BMI), fat mass, obesity, type-2 diabetes, leptin, and insulin-related traits; Duncan et al., 2017; Hübel et al., 2019a; Watson et al., 2019] have also been observed, further indicating metabolic components to AN disease risk. This evidence concerns the gene INS and type 2 diabetes mellitus.