12 Ways Being a Night Owl Could Hurt Your Health

Weight gain: Countless studies have found that people who sleep less are more likely to be overweight. That's probably because sleep deprivation messes with the hormones that regulate your appetite (ghrelin) and tell your brain you're full (leptin), which can lead to chronic overeating, according to a review of experimental and observational studies of sleep published in The American Journal of Human Biology.