Why your body burns fewer calories when you eat less
Effect of caloric restriction on organ size and its contribution to metabolic adaptation: an ancillary analysis of CALERIE 2
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Metabolic adaptation persisted at 24 months and was invisible when using body weight alone.
Most people assume metabolism adapts only during active weight loss—but this shows it keeps slowing down even after weight stabilizes, and you can’t see it on a scale.
Practical Takeaways
If you're trying to lose weight, expect your metabolism to slow down more than expected—plan for maintenance phases with gradual calorie increases to avoid rebound.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Metabolic adaptation persisted at 24 months and was invisible when using body weight alone.
Most people assume metabolism adapts only during active weight loss—but this shows it keeps slowing down even after weight stabilizes, and you can’t see it on a scale.
Practical Takeaways
If you're trying to lose weight, expect your metabolism to slow down more than expected—plan for maintenance phases with gradual calorie increases to avoid rebound.
Publication
Journal
Scientific Reports
Year
2025
Authors
K. Falkenhain, Leanne M. Redman, Wendy Y. Chen, Corby K. Martin, Eric Ravussin, Wei Shen
Related Content
Claims (6)
Even when you're sitting still, your liver and heart are burning a lot of energy—more than other organs—so the bigger these organs are, the more calories your body uses just to keep them running.
When you repeatedly eat fewer calories but still get all the good nutrients, your body adjusts to burn energy more efficiently and becomes less resistant to losing weight.
When healthy, normal-weight people eat 25% fewer calories for two years, they lose weight—but their bodies also burn even fewer calories at rest than you’d expect just from losing weight, as if their metabolism slows down on its own.
When healthy people eat 25% fewer calories for two years, their liver, heart, and muscles shrink a bit, which helps their body adjust to less food—but their brain and kidneys stay about the same size as people who eat normally.
Scientists found that using MRI scans to estimate how much energy your body uses at rest is a bit better than just using your weight or body scan data—but it doesn’t help much more in spotting when your metabolism slows down in response to dieting.