Losing 80 Minutes of Sleep Per Night Leads to Weight Gain Over Six Weeks
A new study finds that cutting sleep by just 78 to 80 minutes per night over six weeks causes measurable weight gain and a drop in physical activity. Researchers say the findings reinforce sleep as a key factor in metabolic health, not just rest.
Cutting sleep by 78 to 80 minutes per night over six weeks is enough to cause weight gain and make people more sedentary, according to new research published in July 2026.
The study tracked participants who reduced their nightly sleep by less than an hour and a half over a six-week period. Researchers measured body weight, physical activity levels, and metabolic markers at the start and end of the study. Participants who slept less gained weight and moved less during the day compared to those who maintained their normal sleep schedules.
The findings add to a growing body of evidence linking sleep duration to metabolic health. Previous research has shown that sleep deprivation raises levels of hunger hormones and reduces the body's ability to regulate blood sugar. This study suggests the effects show up even with modest, sustained reductions in sleep time.
Researchers said the results are relevant for people who routinely cut sleep during the work week and try to catch up on weekends. That pattern, sometimes called social jet lag, does not appear to fully offset the metabolic effects of weekday sleep loss.
Public health experts say most adults need seven to nine hours of sleep per night, but surveys consistently show that a large share of the population falls short of that target. Work schedules, screen time, and stress are among the most commonly cited barriers.
The study authors recommend treating sleep as a health priority on par with diet and exercise, rather than a variable to be sacrificed when schedules get tight.
