The Claim

Sleep restriction to two-thirds of normal sleep time for 8 days increases daily caloric intake by an average of 559 kcal in healthy adults, with no concurrent change in activity energy expenditure, suggesting a potential mechanism for weight gain in individuals with chronic sleep loss.

Source: Effects of experimental sleep restriction on caloric intake and activity energy expenditure.

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
59score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

How it works
1 study reviewed
In plain English

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.

See the scientific wording

Sleep restriction of two-thirds of normal sleep time for 8 days increases daily caloric intake by an average of 559 kcal in healthy adults, with no concurrent change in activity energy expenditure, suggesting a potential mechanism for weight gain in individuals with chronic sleep loss.

What the research says

1 study
  1. Study: Effects of experimental sleep restriction on caloric intake and activity energy expenditure.

    The study made people sleep much less for 8 days and found they ate about 559 extra calories a day without moving more — exactly what the claim says. This could explain why people who don’t sleep enough tend to gain weight.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.