Losing 78 Minutes of Sleep Per Night Leads to Weight Gain Over Six Weeks, Study Finds
A new study found that losing just 78 minutes of sleep per night over six weeks is enough to cause measurable weight gain. Researchers also found that sleep-deprived participants were less physically active during the day, compounding the effect on body weight.
Cutting less than 80 minutes of sleep per night is enough to cause weight gain over six weeks, according to new research published in July 2026.
Researchers found that participants who lost 78 minutes of nightly sleep gained weight and became less physically active compared to those who maintained their normal sleep schedules. The study tracked participants over six weeks, measuring changes in body weight, activity levels, and eating habits.
Sleep-deprived participants moved less during the day, which researchers said compounds the effect of any changes in appetite or calorie intake. The combination of reduced activity and disrupted hunger hormones creates conditions that make weight gain more likely.
Previous research has linked poor sleep to higher levels of ghrelin, the hormone that signals hunger, and lower levels of leptin, the hormone that signals fullness. This hormonal shift can lead people to eat more, particularly high-calorie foods, even when they are not truly hungry.
The findings add to a growing body of evidence that sleep is a critical factor in weight management, alongside diet and exercise. Public health experts have long recommended seven to nine hours of sleep per night for adults, but surveys consistently show that a large share of Americans fall short of that target.
Researchers said the study is notable because the sleep loss involved was modest. Many people lose similar amounts of sleep due to work schedules, screen time, or stress without recognizing the health consequences.
Experts recommend treating sleep as a health priority on par with nutrition and physical activity. Consistent sleep and wake times, limiting screen exposure before bed, and keeping the bedroom cool and dark are among the most commonly recommended strategies for improving sleep quality.
