Does menopause cause weight gain?

Weight gain during perimenopause and menopause is common, and the NHS says it often settles around the stomach and upper body (NHS, Symptoms of menopause and perimenopause). The clearest long-term study of the question found that the transition itself doubles the rate at which women gain fat and starts a slow loss of muscle, while the yearly rise in body weight stays about the same as it was in the years before.

So the honest answer to "can menopause cause weight gain" is that ageing and menopause both play a part, and the part that belongs to menopause shows up in your shape and strength sooner than on the bathroom scale.

What a 1,246-woman study measured

The Study of Women's Health Across the Nation (SWAN) is a long-running project funded by the US National Institutes of Health. In 2019 its researchers published body scans of 1,246 Black, Chinese, Japanese and White women, taken at repeated visits over many years, and lined each woman's results up against the date of her final period (Greendale and colleagues, JCI Insight, 2019). Counting from that date, rather than from a birthday, is what lets a study separate the effect of menopause from plain ageing. The women's last periods came at 52 on average.

For the average woman in the study, the scans showed this:

• Before the transition, fat mass grew by about 0.25 kg a year and lean mass (mostly muscle) grew a little too.
• Once the transition began, fat gain rose to about 0.45 kg a year, close to double.
• Over the same years lean mass went into reverse, falling by about 0.06 kg a year.
• Body weight kept climbing at a steady pace, about 0.25 kg a year during the transition, with no sudden jump when it started.

The authors' conclusion is that faster fat gain and the loss of lean mass are tied to the menopause transition itself. The overall rate of weight gain did not change when the transition began, so the scale gave little sign of the shift underneath. That fits the common experience of a body that feels different while the number barely moves.

These are averages from a large group. Your own figures can be higher or lower, and the study found that race and the age at which periods stopped changed the rates for some women.

Perimenopause weight gain: when it starts

In the SWAN scans, the shift toward more fat and less lean mass began roughly two years before the final period, which for most women is well inside perimenopause and before periods have stopped. The National Institute on Aging says most women begin the transition between 45 and 55, and that during it the body begins to use energy differently, fat is stored in different places and weight comes on more easily (NIA, What is menopause?).

The same page puts it in plain terms: your waist could get larger, and you could lose muscle and gain fat. If your clothes fit differently at 47 while your weight looks the same as at 42, that matches what the research describes.

How long does menopause weight gain last?

In SWAN, the faster fat gain and the muscle loss carried on until roughly two years after the last period. After that, the average changes in fat and lean mass levelled off, and the rise in body weight flattened as well.

Put together, the window the study links to menopause lasts around four years, starting ahead of the last period and ending after it. Other symptoms run longer: the NHS says menopause symptoms usually last 7 to 9 years, sometimes more. Weight after menopause is then shaped by the same everyday things as at any age, such as how active you are, what you eat and how well you sleep.

In the study, lean mass stopped falling after that window but did not climb back to where it had been. The muscle has to be rebuilt on purpose, and that is the job of strength training.

Where muscle fits in

Losing muscle with age has a name, sarcopenia. The National Institute of Arthritis and Musculoskeletal and Skin Diseases notes that older adults tend to lose muscle and that strong muscles help with balance and with avoiding the falls that break bones (NIAMS, Exercise for your bone health). It explains that resistance training makes muscles work harder and loads the bones, which can strengthen the bones too. Bone is the other thing this stage of life takes: NIAMS calls osteoporosis the major cause of fractures in postmenopausal women.

The NHS advice for menopause points the same way. Its list of things you can do includes regular exercise with a focus on weight-bearing exercises to build strength, and a healthy, balanced diet (NHS, Things you can do to help menopause and perimenopause symptoms). The general adult guidelines ask for strengthening activities that work every major muscle group on at least two days a week, on top of 150 minutes of moderate activity such as brisk walking (NHS physical activity guidelines).

If these years tilt your body toward fat and away from muscle, lifting is the habit aimed squarely at the muscle side. For a woman in her late forties I would start with two strength sessions a week, before changing what she eats, since the scans show muscle is the part that begins going backwards in these years. Our guide to strength training during menopause covers how to start at home with a chair and a wall, and the 4-week strength plan sets out the first month for your starting level. For the whole routine, with walking and meals around the lifting, see how to prevent menopause weight gain.

Judge progress by more than the scale

Since the scale can stay flat while fat goes up and muscle goes down, it is a poor guide on its own in these years. Three measures tell you more:

• Your waist, measured at the same point once a month, since the NHS names the stomach as a common place for the weight to settle.
• Your strength, such as how many slow sit-to-stands from a chair you manage, or the weight you curl.
• A weekly average of your weight instead of a single daily reading, because water and the last meal can move the number from one morning to the next.

A notebook covers all three, with one line a week. Weigh yourself on the same three or four mornings, before breakfast, and write down the average for the week next to your waist and your sit-to-stand count. After two or three months the trend in those three numbers says far more about what menopause is doing to your body than any single day on the scale.

When to talk to a doctor

The NHS suggests contacting a GP if you think you have symptoms of perimenopause or menopause and want to know your options. The NIA adds that if you are worried about changes in your body, you should follow up with a doctor. Weight that comes on quickly, or with other changes you cannot explain, is worth raising at an appointment instead of putting down to menopause. Before you start lifting, the NHS advises speaking to a GP if you have not exercised for some time or have a health condition, and NIAMS asks anyone told they have low bone density to check with a healthcare provider which exercises are safe for them.