Finally, IR is accompanied (and possibly caused by) elevated IMTG [66] and the associations between obesity, elevated IMTG, and IR might imply alterations in accumulation of lipid in muscle and blunting of insulin action that conspire to create a different pattern of exercise fuel use for overweight/obese individuals with IR compared to normal-weight individuals without it. The gene discussed is INS; the disease is obesity due to melanocortin 4 receptor deficiency.