Results of Diabetes Control and Complications Trial (DCCT) indicated that during the first year of intensive insulin therapy subjects gained more weight (5.1 ± 4.6 kg) than participants treated conventionally (2.4 ± 3.7 kg) (76), and over the course of 6.5 years of the same study about 25% of subjects who were treated with intensive insulin therapy gained more weight than group treated in conventional way what resulted in occurrence of obesity (77). The gene discussed is INS; the disease is obesity due to melanocortin 4 receptor deficiency.