Several studies have determined that obese individuals (or those with a high BMI) have a higher risk of recurrence than non-obese individuals; the underlying mechanism is considered to be the fact that obesity increases the insulin and IGF-1 levels, pushing non-advanced colorectal polyps into the advanced stage and causing recurrence [12, 33, 34]. The gene discussed is IGF1; the disease is obesity due to melanocortin 4 receptor deficiency.