The role of clock genes such as Cryptochrome circadian regulator (CRY1-2) (Cryptochrome circadian regulator), Period Circadian Regulator (PER1-3), Circadian locomotor output cycles kaput (CLOCK), and Brain and muscle Arnt-like protein-1 (BMAL1) is maintaining circadian rhythms and any disturbance in those genes could induce metabolic imbalances like obesity [86]. Here, CLOCK is linked to obesity due to melanocortin 4 receptor deficiency.