We found that the obesity-risk variant in intron 1 of the fat mass and obesity–associated (FTO) gene was replicably inversely associated with the So-Eum (SE) type, characterized by reduced appetite, slim body, and cautious personality (rs7193144 in combined samples: odds ratio = 0.729, p = 1.47 × 10−7), and substantial association signal remained after controlling for body mass index (BMI). Here, FTO is linked to obesity due to melanocortin 4 receptor deficiency.