The increase in the incidence of cancer, diabetes, cardiovascular disease, and psychiatric disorders (70–72), might also be related to disruption of sleep-wake rhythms, impaired secretion of melatonin from nighttime light, combined with obesity and a tendency to produce reactive oxygen species (73), which also affects the circadian rhythm of GLP-1 secretion. This evidence concerns the gene GCG and obesity due to melanocortin 4 receptor deficiency.