Your grandparents were onto something with those early-bird dinners: The best time to eat the evening meal is four hours before bedtime.
Peak dinnertime in America is 6:19 p.m., but it varies from a little after 5 p.m. to after 8 p.m., depending on the part of the country, according to a statistician who analyzed time-use data from the U.S. Bureau of Labor Statistics. Nutritionists vary on when dinner should be served but agree it should be at least two hours before bedtime.
The most important factor in the dinnertime calculus is melatonin, the hormone that signals it’s time to sleep, says Satchidananda Panda, a professor at the Salk Institute for Biological Studies.
Melatonin, which begins to rise about three hours before we go to bed, also tells the pancreas to cut back on insulin production. If we have a sugar spike after eating late, our body has a harder time regulating blood sugar, Panda says. This could put us at risk of diabetes and other metabolic disorders. For that reason, he says the ideal dinnertime is three to four hours before bed.