In addition, staying up late is a common major risk factor for non-communicable diseases (NCDs), including cardiovascular disease (CVD), diabetes, and cancer.37–39 Ultimately, an unhealthy lifestyle alters the biological rhythm or circadian clock, which then affects the human immune system.39 Unfortunately, the Kailuan study did not collect the information on the overall calorie intake and sleep rhythm. This evidence concerns the gene CLOCK and diabetes mellitus.