The body burns less after weight loss
- Published in
- NEJM 1995
- People studied
- 41
In 41 adults kept 10% or more below their usual weight, the body burned less energy for each kilogram of lean (non-fat) body mass, a change that works against keeping the weight off.
- Checked against
- PubMed 7632212
- Published in
- NEJM 1995
- Last checked
- 30 October 2026
Key takeaway
Researchers studied 18 people with obesity and 23 who had never had obesity at their usual weight, after losing 10 to 20% by eating less, and after gaining 10% by eating more. Staying 10% or more below their usual weight went with daily energy use about 6 to 8 calories lower per kilogram of lean body mass, in both groups. Gaining weight raised energy use, so in both directions the body's energy use changed in a way that resists a new weight.
At a glance
- Type of study
- small laboratory study of controlled weight loss and gain
- People studied
- 41
- Compared with
- people who had never had obesity, and each person's own usual weight
- Main result
- Daily energy use fell about 6 to 8 calories per kilogram of lean (non-fat) body mass.
- Strength of evidence
- Small or uncontrolled studies
What this study does not show
A small study with weight changed on purpose under close laboratory control. It does not show how large the effect is in everyday life or over years.
Results from studies in groups of people, mostly in diet and movement programmes. They cannot be promised to any one person. This information is educational and does not replace a consultation with a doctor.
More on why
- Genes explain much of the difference in BMILong-term or observational studies · Stunkard et al., NEJM 1990
- Years of lifeLong-term or observational studies · Prospective Studies Collaboration, Lancet 2009
- Heart failure riskLong-term or observational studies · Kenchaiah et al., NEJM 2002
- Fatty liverLong-term or observational studies · Quek et al., Lancet Gastroenterol Hepatol 2023
- The body burns less after weight lossSmall or uncontrolled studies · Leibel et al., NEJM 1995
- Four or more illnesses at onceLong-term or observational studies · Kivimäki et al., Lancet Diabetes Endocrinol 2022
The next step is a conversation, not a decision
A licensed doctor decides whether any treatment is right for you. The answer can also be no treatment.
1You fill in a short form
2We call you within 24 hours
3A paid 20-minute video consultation with a doctor
4The doctor goes through your options and decides what is right for you