We know that a lack of sleep is bad for your health, but what about too much sleep? Researchers from South Korea set out to answer that question…

Researchers analyzed medical data of 133,608 men and women aged 40–69. Participants reported how much they slept each day, including naps.

Researchers found ties to metabolic syndrome with both too much and too little sleep. Even more interestingly, women were at a higher risk for metabolic syndrome than men when sleeping too much.

So, women who slept less than 6 hours per day were likelier to have a higher waist circumference, indicative of excessive belly fat, than women who slept for 6–7 hours per day. Comparatively,
men who slept for less than 6 hours were more likely to have not just a higher waist circumference, but also metabolic syndrome.

Oversleeping had a detrimental effect as well. Men who slept for 10 hours each day had a higher incidence of raised triglyceride levels and metabolic syndrome. In women, sleeping for 10 hours each day was associated with even more negative health outcomes: metabolic syndrome, high triglyceride levels, high blood sugar, low HDL cholesterol, and higher waist circumference.