Genetics vs. Exercise: What Causes Postmenopausal Weight Gain?

Health Writer
Medically Reviewed

I’ve seen hundreds of clients over the years as a Physician Assistant, and more recently as a health coach. The primary reason I meet with an individual is to help with weight loss efforts. It’s typical to try and find out why the person thinks they’re struggling with weight gain or obesity. Some of the recurring answers include:

  • I don’t know why I am gaining weight.
  • I think I eat the same amount as other people, so it can’t be what I’m eating.
  • I don’t even eat breakfast or lunch most of the time, so it must be my metabolism.
  • Almost everyone in my family was thin, like me, until middle age and then the weight just started piling on, so it’s my destiny.
  • I’ve always had a weight issue – it’s genetic.
  • It’s my thyroid.

Women who come to me with weight gain during late perimenopause and menopause often have a standard set of answers regarding their weight gain. They often share that:

  • I never had to watch what I was eating and suddenly I am gained weight, especially in my belly area. I heard menopause causes weight gain.
  • I know it’s inevitable to gain weight as I get older. My metabolism is slowing down, right?
  • This is exactly what happened to my mom when she hit menopause.
  • I haven’t changed my diet at all, so it must be my thyroid or some other condition must be contributing to my weight gain.

It’s important to have the facts about weight gain, especially during the middle years of life. If you were lucky enough to have a somewhat efficient metabolism when you were younger, it will naturally slow down during the aging process, especially if you don’t maintain enough muscle mass to support your energy balance. We all lose muscle mass as we age because of lower hormone levels – men have declining testosterone levels, and women have declining estrogen levels. Estradiol deficiency causes significant changes in metabolism that result in increased food intake and meal size, increased deposition of visceral fat, altered fat distribution, increased lipid accumulation, and insulin resistance. Additionally, if you’re not actively engaged with weight-bearing (resistance) training, or minding your calories, then yes, you will likely gain weight if you don’t introduce this type of exercise regularly or eat less.

Avoiding weight gain

Weight gain is not inevitable, except in a few dire health circumstances like Prader-Willi syndrome. In most cases, people are either eating too many calories, or not burning off enough of the excess calories being consumed because of limited exercise and daily physical activity. Some people have an adequate energy balance and burn off all the excess calories they consume. Most of us have a normal metabolic rate and just eat too much, move too little and don’t maintain muscle mass.

Your lifestyle choices are largely enabling weight gain during menopause. If you’re an emotional or stress-eater, consuming too many salty, sugary or fatty foods, you will indeed pack on the pounds. However, a 2018 study suggests that genetic predisposition to weight gain and obesity can be thwarted with exercise efforts, especially during menopause.

In a study published online in Menopause, the journal of The North American Menopause Society (NAMS), researchers acknowledged that there are genetic influences on body mass index (BMI) increases from childhood to adulthood. How the genetic influences persist later-in-life, especially during the middle years, when women experience menopause, had not been studied extensively. The goal of this study was to examine genetic predisposition for weight gain. In other words, they wanted to know if genes can cause inevitable weight gain.

The researchers found that there is a perpetuated genetic influence on weight gain, but exercise (especially weight bearing or muscle building) could attenuate and limit the genetic influence. In simple terms, exercise prevents weight gain in mid-life and can intercept weight gain as you get older.

Exercise helps at any age

In a ScienceDaily interview, Dr. JoAnn Pinkerton, NAMS executive director, affirms that even as women get older, exercise (specific types) can build or maintain bone and muscle mass, invigorate brain cells, improve mood, concentration, and cognition, and even limit arthritis-related pain. She acknowledges that at any age, regardless of the amount of excess fat you may have, exercise efforts can also help to improve one’s health profile.

I personally have witnessed successful weight maintenance or weight loss in menopausal women who never exercised regularly. My experience is that introducing exercise coupled with serious dietary modifications focused on calories and quality of food – are often necessary to help to reverse weight gain and prevent future weight issues. Exercise alone can help to burn calories and nudge some weight loss, but it is mostly the amount and types of food we choose that fuel weight gain. Yes, some of us will always gain weight more easily which means that we start life with a slightly less efficient metabolism. Calorie control and exercise can address that issue and our lifestyle can be tweaked as we move through the decades, to make sure we continue to be vigilant and mindful of our weight.

Setting weight goals

If you enter menopause watching your calorie intake and doing the right types of exercises regularly, you can thwart your genes and prevent weight gain. Ask your doctor for a referral to a dietician or nutritionist who can help you to manage your daily dietary choices and weight goals. You may also want to ask about estrogen replacement therapy.

If you don’t exercise, then consider hiring a personal trainer for a few sessions, so you can learn about resistance training and create a workout program. Intermittent visits with these professionals can help you to stay on track. If you already diet and exercise, meeting with these professionals can be an eye opener, helping you to adjust and improve your current lifestyle habits. Just remember that weight gain in menopause is not inevitable – unless you surrender the control.