CLOCK and metabolic disease: On the other hand, mice with a genetically disrupted circadian clock display disrupted feeding rhythms and high propensity to metabolic disease [59, 77, 78]. Per1 mutant mice have constantly high corticosterone levels and fail to gain weight as efficiently as wild type animals despite the high body weight-adjusted food intake, suggestive of increased metabolic rate, along with increased glucose metabolism that the authors attribute to the lack of a robust glucocorticoid rhythm [78].