SWAN, 3,064 women, 3 years
+2.1 kg and +2.2 cm of waist
The average gain over three years of follow-up, in women aged 42 to 52 at the start. Change in menopausal status was not linked to weight gain.
The body at menopause · weight and composition
Through the menopause transition, the scale climbs at the same pace. Fat climbs almost twice as fast.
The American SWAN study scanned the bodies of 1,246 women at almost yearly visits, up to 13 times each. When the transition began, the pace at which weight rose stayed practically the same. Beneath it, fat gain sped up from 0.25 to 0.45 kg a year, and lean mass, which had been rising slightly, began to fall.
Beneath the number on the scale
Eight years before, ten after: what builds up beneath the same scale.
The lines show how much has built up, on average, since eight years before the last period. The dashed line is fat plus lean mass. Weight measured in the study rose by 0.25 kg a year in the transition, at the same pace as before; the sum, computed from its two components, speeds up by only 80 grams a year. The yellow band is the transition as the study's model defines it: from two years before to a year and a half after the last period.
Fat + lean mass
Fat
Lean mass
| Per year, on average | Before (−8 to −2 years) | Transition (−2 to +1.5) | After (+1.5 to +10.5) |
|---|---|---|---|
| Fat | +0.25 kg | +0.45 kg | ≈ 0 |
| Lean mass | +0.06 kg | −0.06 kg | ≈ 0 |
| Fat + lean mass | +0.32 kg | +0.40 kg | ≈ 0 |
Years relative to the last period. The sum of the two speeds up by just 80 grams a year, and for weight the study finds no change of pace at all. For fat, the speed-up is 199 grams a year; for lean mass, the pace drops by 119 grams.
The waist
Fat doesn't just grow. It moves towards the belly.
The International Menopause Society (IMS) calls falling oestrogen the main cause of fat building up around the abdomen in midlife. The waist grows even in women whose body mass index stays normal throughout the transition.
That matters. IMS notes that women with a normal body mass index and a large waist have cardiovascular mortality comparable to women with both a raised index and a large waist. So IMS says body mass index without a measure of central fat is not a satisfactory marker.
Meta-analysis, 201 cross-sectional and 11 longitudinal studies
After menopause: +4.6 cm of waist, −3.2% leg fat
Comparing women after and before menopause, a meta-analysis finds a bigger waist and more fat on the trunk, but less on the legs. The authors put the overall difference down to age, and see the shift in fat as a possible effect of menopause.
Age or menopause
The kilos come mostly with age. The shape of the body changes with menopause.
IMS 2026 sums up the evidence like this: midlife weight gain is mostly a result of ageing, not of menopause. The average it quotes is 0.7 kg a year, higher than in the SWAN analysis above, which uses a different method and a different sample. The dominant explanation is the fall in lean mass and physical activity with age. Studies that followed women over time found a lower calorie intake in this period, not a higher one.
The pattern is not universal. In SWAN, Japanese women gained no extra fat during the transition, and a later menopause meant a smaller speed-up.
HRT and medicines
Hormone therapy doesn't make you gain weight. Nor does it make you lose it.
Cochrane, 28 randomised trials
No difference in weight
Compared with women not taking HRT: +0.03 kg with oestrogen alone and +0.04 kg with oestrogen and progestogen, neither difference statistically significant. Body mass index did not differ either. The search for studies ended in 2005.
IMS 2026, grade A recommendation
Not for weight loss
HRT is not used for weight management or to improve body composition. It has a mildly favourable effect on belly fat and muscle mass, but IMS considers it of minor clinical significance. Its risks and benefits are on the treatment page.
Medicines that can affect weight
Some can add kilos
IMS lists as possibly linked to weight gain gabapentin, clonidine, paroxetine, citalopram, amitriptyline, imipramine, mirtazapine and clozapine. As weight-neutral: escitalopram, sertraline, fluoxetine, venlafaxine, desvenlafaxine, fluvoxamine, fezolinetant, elinzanetant and oxybutynin. The doctor weighs other factors too, not only weight.
What helps
IMS recommends moderate exercise and two strength sessions a week.
IMS recommends at least 150 minutes a week of moderate exercise, plus two sessions of resistance exercise, which bring extra benefit. For bone, IMS cites the World Health Organization advice: exercises for all the major muscle groups on at least two days a week.
Because body mass index alone is not enough, the waist is worth measuring at the appointment. Blood pressure, blood sugar and lipids complete the picture. A rapid or unexplained change in weight deserves its own assessment, for other causes.
Sources
Where the numbers come from.
- Greendale GA et al., Changes in body composition and weight during the menopause transition, JCI Insight, 2019
SWAN, 1,246 women (356 Black, 153 Chinese, 178 Japanese, 559 White), average age at the last period 52.2, DXA measurements. The chart's annual rates are those of the average participant in the published model. The study's abstract says the changes continue until two years after the last period; the model uses a year and a half, and the chart follows the model. - International Menopause Society, Recommendations on Women’s Midlife Health and Menopause Hormone Therapy, 2026
The section on midlife body changes (PDF pp. 15–17): 0.7 kg a year, the roles of age and oestrogen, the waist at normal body mass index, HRT and weight, medicines; the exercise recommendation. - Sternfeld B et al., American Journal of Epidemiology, 2004
SWAN, 3,064 women, three years: +2.1 kg, +2.2 cm of waist. - Ambikairajah A et al., American Journal of Obstetrics and Gynecology, 2019
Meta-analysis: women after versus before menopause, waist +4.63 cm, leg fat −3.19%. - Kongnyuy EJ et al., Cochrane Database of Systematic Reviews, CD001018
The effect of HRT on weight: 28 randomised trials, 28,559 women, search ended July 2005.