As there are no published studies either for the MC4R or for the FTO genes that have analyzed their interactions with MedDiet on type 2 diabetes, our main objective was to evaluate whether adherence to the MedDiet pattern modifies the association of the FTO rs9939609 and MC4R rs17782313 polymorphisms with type 2 diabetes, either independently or jointly. Here, FTO is linked to type 2 diabetes mellitus.