Changes to Body Composition after Menopause

 

Many body systems respond to the change that menopause introduces. Let’s explore changes to: 

1. Fat distribution 
2. Muscles 
3. Bones

 

Fat distribution

Many women surveyed by Acro reported experiencing ‘stubborn, midsection fat’ following menopause. This is a common description of a new distribution of fat around the waist, known amongst health professionals as central adiposity. 

Whilst central adiposity can be associated with weight gain, in postmenopausal women it is a symptom of a change in body composition whereby the body carries more ‘fat-mass’ and less ‘non-fat mass’ such as muscle and bones.

Central adiposity is a sign of increased visceral fat. Visceral fat is a type of fat stored deep within the abdominal cavity, surrounding our internal organs such as the liver, pancreas, and intestines. It differs from subcutaneous fat, which is located just beneath the skin. Visceral fat can promote chronic inflammation, interfere with metabolic processes and ultimately put you at risk of chronic diseases including type 2 diabetes and cardiovascular disease. (1) 

As well as having negative implications for long-term health outcomes, central adiposity and an increased weight are associated with more severe vasomotor symptoms including hot flashes, and night sweats, as well as insomnia. (2)

Fluctuations in weight are a result of the amount of energy consumed in food and drinks (measured in calories or kilojoules) and the total amount of energy used throughout the day. Total energy expenditure is made up of three components;

1. Basal metabolic rate (the energy your cells burn in the background) 
2. Energy expenditure from activity (like walking, working out or doing the gardening)
3. Dietary induced thermogenesis (energy burned from the digestion of food).

With age, our basal metabolic rate (BMR) decreases. This means that the body requires fewer calories to maintain its basic physiological functions. Interestingly, a reduction in muscle mass has been attributed to be one of the strongest determinants of a reduction in BMR with age (3). 

Without proper adjustment to dietary or exercise habits, a decrease in BMR alone can easily contribute to weight gain. Pioneering research suggests that a solution to this problem may lie in our protein consumption. Read more on our blog changes to protein requirement across midlife and beyond. 

 

Muscles

Women are particularly prone to a faster rate of muscle loss as they age. This has been explained by two compounding mechanisms associated with both ageing, and menopause. The first impacts both men and women, and is an impaired ability to build new proteins and muscle tissue from the dietary protein we ingest as we age. The second mechanism is enhanced protein breakdown due to a lack of oestrogen, affecting postmenopausal women. (4)

 

Bones 

Another change in body composition associated with menopause is a decrease in bone density. This reduction is primarily due to decreased levels of oestrogen. Research indicates that postmenopausal women can lose up to 20% of their bone density within the first five years following menopause, significantly increasing their risk for osteoporosis and fractures. These changes underscore the importance of monitoring bone health with your GP and considering preventive measures, such as lifestyle modifications (see our blog Menopause and bone health) and possibly hormone replacement therapy, to mitigate the effects of menopause on bone density. (5)

 

In summary, menopause is a strong predictor of increased central fat deposition and waist circumference. This carries increased risks of metabolic and cardiovascular disease (3). The oestrogen deprivation experienced after menopause also puts women at risk of low bone density (osteoporosis) and low muscle mass which not only contributes to a change in physical body composition, but also has serious implications for functionality and independence with age. 

 

References: 

1. Fenton, A. (2021). Weight, shape, and body composition changes at menopause. Journal of Midlife Health, 12(3), pp. 187–192. DOI: https://doi.org/10.4103/jmh.jmh_123_21.
2. Marlatt, K.L., Pitynski-Miller, D.R., Gavin, K.M., Moreau, K.L., Melanson, E.L., Santoro, N., & Kohrt, W.M. (2021). Body composition and cardiometabolic health across the menopause transition. Obesity, 30(3). DOI: https://doi.org/10.1002/oby.23289.
3. Hurtado, M.D., Saadedine, M., Kapoor, E., Shufelt, C.L., & Faubion, S.S. (2024). Weight gain in midlife women. Current Obesity Reports, 13, pp. 352–363. DOI: https://doi.org/10.1007/s13679-024-00555-2
4. Simpson, S.J., Raubenheimer, D., Black, K.I., & Conigrave, A.D. (2022). Weight gain during the menopause transition: Evidence for a mechanism dependent on protein leverage. BJOG: An International Journal of Obstetrics & Gynaecology, 130(5), pp. 701-709. DOI: https://doi.org/10.1111/1471-0528.17290.
5. Shieh, A., Karlamangla, A.S., Karvonen-Guttierez, C.A., & Greendale, G.A. (2023). Menopause-Related Changes in Body Composition Are Associated With Subsequent Bone Mineral Density and Fractures: Study of Women’s Health Across the Nation. *Journal of Bone and Mineral Research*, 38(3), pp. 395–402. DOI: [10.1002/jbmr.4661](https://doi.org/10.1002/jbmr.4661)