07/09/2026
Why does weight gain happen in perimenopause?
A lot of people blame hormones. Others say it’s just aging. The truth is, it’s both.
Here’s the Menopause Society’s position on why weight gain happens in midlife and around the menopausal transition.
First, we naturally lose muscle as we age—about 3–8% per decade after age 30 if we’re not actively working to maintain it.
Why does that matter?
Muscle burns more calories than fat. So as muscle declines, you need fewer calories to maintain your weight. This means the amount of calories that maintained your weight at 35 may slowly become too much at 50.
Then menopause adds another layer.
As estrogen levels fall, your body changes where it stores fat. Instead of storing fat around the hips and thighs, we shift to storing more fat around the abdomen.
So even if there’s not much change on the scale, your clothes might start fitting differently, and you might notice an increase in your waistline.
Now add in real life.
Sleep becomes worse because of night sweats, stress, or many other causes. Many women are juggling careers, teenagers, aging parents, or all of the above.
Energy is lower, so workouts become less consistent. When you’re tired, stressed, and not sleeping well, it’s really hard to make healthy choices.
We also know that menopause decreases something called non-exercise activity thermogenesis (NEAT). These are the calories burned from activity that is not formal exercise. This happens even when your exercise level stays the same.
Women often shift to a more sedentary lifestyle without even realizing it.
So it’s not that your metabolism suddenly stops working. It’s that several small changes add up at once.
Knowing this helps us put together a plan to manage it without hopping on every weight-loss trend and getting lost in diet cycling.