FTO and obesity due to melanocortin 4 receptor deficiency: In addition, we thought that analyses using the “current BMI”, as conducted in many previous studies [1,9–17,19,20], might underestimate the influence of obesity on the association of FTO variants with T2D, and that the BMImax before or at the time of T2D onset, rather than the“current BMI”, might be a better variable for understanding the precise mechanisms of the effects of FTO variants on the susceptibility to T2D for the reason mentioned in the Introduction section.