It’s a very common complaint: once a woman stops cycling, even if she never had any issues with her weight before, suddenly it’s a lot harder to keep the pounds off. Why is this? What’s the connection between female hormones and weight?

Estrogen, Insulin Resistance, and Metabolic Syndrome

This study establishes that the lower estrogen levels of menopause affect the body’s metabolism and insulin resistance. How it does this is multifactorial, including direct effects on insulin signaling, effects on insulin release via the pancreas, effects on hunger, on glucose production via the liver, and on how the body maintains or breaks down fat in certain areas.

The most obvious effects of estrogen on fat can be seen in body shape. Estrogen is responsible for the deposition of fat in a woman’s body in the hips and buttocks (the classic “pear shape”)—even an exercising or calorically depleted woman will tend to maintain that shape, as estrogen discourages fat breakdown in those areas.

But in the absence of estrogen, that’s no longer true—post-menopause, the body tends to put any excess weight in the abdomen (the “apple shape” more associated with Metabolic Syndrome and cardiovascular risk.)

Testosterone and Weight Loss (or Gain)

Testosterone in menopause can be a double-edged sword, depending on how much is given. On one hand, testosterone helps to encourage the body to increase muscle and decrease fat.

But too much testosterone can actually contribute to insulin resistance. This is probably because androgens, including testosterone and DHEA, will decrease Sex Hormone Binding Globulin (the carrier molecule to prevent hormones from stimulating receptors). Low SHBG is associated with increased risk of insulin resistance and diabetes.

So it’s another one of those Goldilocks principles: have enough, but not too much.

The Upshot

If you’ve experienced new onset of any of the symptoms associated with Metabolic Syndrome after menopause, consider adding bioidentical hormones into your regimen, based on your lab levels and symptoms.