Sleep deprivation ratchets up the stress system, leaving you more susceptible to even relatively mild sources of strain. When University of Chicago researchers led by Eve Van Cauter deprived young, healthy people of a few hours of sleep for six nights, they produced in them the hormonal profiles of much older people: higher levels of stress hormones and lower levels of growth hormone (essential to cell repair). The study’s participants developed hormonal imbalances conducive to weight gain and levels of insulin resistance like those of people with diabetes.
