Obesity, particularly abdominal obesity may be correlated with an increased activity of the rate-limiting step in cholesterol synthesis, the hepatic enzyme, 3-hydroxyl-3-methyl-glutaryl co-enzyme A (HMG-CoA) reductase, leading to increased cholesterol synthesis in the liver and its heightened secretion into bile [31]–[33]. The gene discussed is HMGCR; the disease is obesity due to melanocortin 4 receptor deficiency.