The causal estimate between fasting insulin and anorexia using both the MR-PRESSO and GSMR approaches was also practically identical to the IVW estimator, although the GSMR estimate displayed a larger standard error (ORGSMR = 0.48, [95% CI:0.30–0.79], P = 3.7 × 10−3). This evidence concerns the gene INS and Anorexia.