FTO and type 2 diabetes mellitus: Because of the extensive literature on the link between chronotype and metabolic disease and because the well-known SNP in FTO (rs1558902) previously associated with higher BMI54,55 was also associated with being a morning person (OR = 1.04, P = 4.9 × 10−32), we also performed two-sample MR against the metabolic phenotypes BMI, type 2 diabetes and fasting insulin levels.