The Study
Effects of experimental sleep restriction on caloric intake and activity energy expenditure.
This study found that when people slept less, they ate more food — but we don’t know if that’s because they were hungrier or just ate more because they were awake longer. We can’t say for sure that less sleep causes weight gain, because we didn’t see people actually gain weight in this short study.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
When people slept much less for a week, they ate a lot more food each day, but they didn't move more or burn more calories. Their hunger hormones didn't change, so something else must be making them eat more.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 559 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — eating 559 extra calories daily without burning more could lead to weight gain over time.
- 2Ate 559 extra calories per day.
- 3No change in movement or hunger hormones (leptin and ghrelin).
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Chest
Year
2013
Authors
Andrew D Calvin, R. Carter, T. Adachi, P. Macedo, F. Albuquerque, C. van der Walt, Jan Bukartyk, Diane E. Davison, J. Levine, V. Somers
Related Content
Claims (4)
If you don’t get enough sleep for 8 days, your hunger hormones don’t change much—so if you end up eating more, it’s probably not because these hormones are telling you to.
If you cut your sleep down to just two-thirds of what you normally get for eight days straight, you’ll likely eat about 559 extra calories a day without moving more—this could be why people who don’t sleep enough tend to gain weight.
When people don’t get enough sleep for eight days, they don’t end up moving more to burn off the extra calories they eat—so they’re likely to gain weight just from eating more, not from being lazy.
If you don’t get enough sleep just one night, your body makes more of the hunger hormone and less of the fullness hormone, which might make you feel hungrier the next day.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.