Do you eat more when you don't get enough sleep?

Short answer

Yes. Cutting sleep made people eat about 253 to 385 kcal more a day, while the calories they burned stayed the same. Appetite hormones did not clearly change, and the extra calories were packed into the late-night hours spent awake.

Do you eat more when you don't get enough sleep?
'Less sleep → more hunger hormones → overeating' — does this formula hold?
A common belief says that when you sleep badly, hunger hormones rise and you overeat. We checked whether people really eat more, and if so, why and when.
People did eat more
About 385 kcal more a day
An analysis that pooled 11 studies (172 people) found that cutting sleep raised daily calorie intake by 385 kcal. Calories burned and resting metabolism did not change. Another analysis of 41 trials found people ate about 253 kcal more a day and gained 0.34 kg.
What did they eat more of?
More fat, less protein
In the 11-study analysis, cutting sleep raised the share of calories from fat and lowered the share from protein. Carbs did not change.
But hormones were not the reason
Appetite hormones did not clearly change
In the 41-trial analysis, hunger rose by 13.4 points out of 100, but average levels of the appetite hormones leptin and ghrelin showed no clear change. In a 16-person trial, people ate more and gained 0.82 kg in 5 days even though their hormones were signaling plenty of energy. A 2026 review also concluded the extra eating was often not explained by changes in hunger.
When did they eat more? During the hours awake at night
About 553 kcal between 10 pm and 4 am
In an experiment where 225 people went to bed at 4 am for 5 nights, the 31 whose intake was measured ate 130% of their daily calorie needs, with about 553 extra kcal between 10 pm and 4 am alone. They gained 0.97 kg, more than the well-rested group (0.11 kg). In the 16-person trial, the extra eating was also concentrated at night after dinner.
The reverse: sleeping more meant eating less
2 more hours of sleep, 270 kcal less a day
In a trial of 80 people who usually slept less than 6.5 hours, those coached to sleep longer gained about 1.2 hours of sleep a night. With no diet plan, they ate 270 kcal less a day over 2 weeks. Their weight ended up 0.87 kg lower than the group that kept their usual routine.
Bottom line: short sleep means eating 253 to 385 kcal more a day
The formula runs through 'nights awake', not hormones
Cutting sleep made people eat about 253 to 385 kcal more a day, while calories burned stayed the same. The extra calories were packed into late-night hours awake rather than driven by appetite hormones. Sleeping 1.2 hours more cut 270 kcal a day, so during a diet you can treat sleep as part of your eating plan.