We recently told you about studies that show getting the right amount of sleep is critical to maintaining a healthy weight. But does it matter when we sleep? Now there’s research from Northwestern University suggesting that staying up late at night can lead to an additional 2 pound a month weight gain.
The findings in the journal Obesity show that people who stay up late and sleep in tend to have worse diets, eat more at night and gain more weight, compared with those who go to bed at a reasonable hour.
For starters, study participants who stayed up late got less sleep overall. The late sleepers ate more fast food and fewer fruits and vegetables.
Interestingly, all together the late sleepers ate roughly the same number of calories per day as normal sleepers. However, they ate a larger proportion of their food at dinner or after 8 p.m. and the researchers found that timing went along with excess weight.
The study reinforces that age-old wisdom that when you eat is important. The study authors say when sleep and eating are not aligned with the body’s internal clock, it can lead to changes in appetite and metabolism.