Indeed, male mice fed on HFD for up to 15-weeks displayed all cardinal manifestations of obesity and MetS, including increased BW, increased calorie intake, increased fat mass and adiposity, hepatic steatosis, elevated serum triglycerides, increased basal glucose and insulin levels, as well as perturbed glucose tolerance and (modestly) worse insulin sensitivity. The gene discussed is INS; the disease is obesity due to melanocortin 4 receptor deficiency.