Several studies have shown a close relationship between the circadian clock system and nutrient metabolism; thus, it is widely established that circadian clock disruptions result in metabolic disorders and ultimately obesity and the related diseases (Rudic et al. 2004, Broberger 2005, Turek et al. 2005, Buijs & Kreier 2006, Oishi et al. 2006, Kennaway et al. 2007, Lamia et al. 2008, Yang et al. 2009, Shimba et al. 2011). This evidence concerns the gene CLOCK and obesity due to melanocortin 4 receptor deficiency.