Muscle, Metabolism, and Menopause: The Real Story Behind Weight Gain in Midlife
Weight changes in perimenopause and menopause are common and the result of several factors, including:
Low levels of estrogen, progesterone, and testosterone
Increased body inflammation
Insulin resistance
A decrease in our resting metabolic rate
A decrease in overall energy expenditure (we aren't moving as much as we once were)
Our dietary choices (both quality and quantity)
The health of our gut microbiome
Current and long-term exposure to toxins and other endocrine-disrupting chemicals (EDCs)
And many other factors.
Muscle mass decreases by approximately 1.5% yearly after age 50 and by 2.5-3.0% yearly after 60. This is a BIG deal and something we must address to remain independent through midlife and into our older adult years.
We also lose our ability to maintain fast-twitch fiber action (i.e., strong, fast muscle contractions) and our overall muscle integrity, which is why we need to change our exercise routine once we hit the pausal years.
Muscle accounts for 30% of our entire body's resting metabolic rate, which means that a loss of muscle means a slower metabolism, which leads to additional weight gain. Research shows that a steady increase in weight, fat mass, and BMI begins several years before menopause,[1].
Not all weight gain in menopause is "bad." A study from the Journal of the American Heart Association challenges the conventional belief that "body fat is bad." UCLA researchers analyzed the body composition and heart disease risk of over 11,000 adults, equally divided between men and women. They found that higher muscle mass was linked to a lower risk of cardiovascular disease death in both genders. Interestingly, for women, higher body fat also correlated with a reduced risk of dying from heart disease, regardless of muscle mass, a trend not observed in men.
Additionally, a study published in Menopause, discovered that lean postmenopausal women who gained 10 kg (22 lbs) or more experienced nearly a threefold decrease in mortality risk. So, there is a reason for midlife weight gain. We tend to overly focus on weight gain, when the priority should be maintaining muscle mass.
Remedies to Reduce Weight Gain and Increase/Maintain Muscle Mass
Nutrition and lifestyle
Increase your protein intake- General protein guidelines to maintain muscle and prevent muscle loss include:
Eating a minimum of 1.2-1.5 grams of protein per kilogram (kg) of body weight per day ~ approximately 20-40 grams of protein per meal.[2],[3]
Dr. Stacy Sims, Ph.D., an expert in sex differences in training, nutrition, and environmental conditions, recommends 2 – 2.4 grams of protein/kg ( 0.7- 1.1 grams/lb per day), evenly distributed every 3 to 4 hours across the day.
Aim for 30-40 grams of protein with each meal and 15-20 grams of protein at snacks in between.Increase protein intake post-exercise, aiming for 40 grams of protein. More protein intake is likely needed for physically active women to prevent muscle breakdown.
Here's how to calculate your protein needs:
Determine how many kg you weigh by converting lbs. to kg
1 kilogram (kg) = 2.2 lbs ~ Use this handy converter to calculate kg to lbs.
Now take your kg and multiply by the recommended grams of protein. Using a 130 lb woman (59 kg) as an example, here are your calculations:
1.2 x 59= 70.8 grams of protein
1.5 x 59=88.5 grams of protein
2.0 x 59 = 118 grams of protein
2.5 x 59 = 147.5 grams of protein
A 130 lb. woman (59 kg) would need a minimum of 70.8 grams of protein per day to maintain muscle mass as she ages; this range will vary depending on her activity level and other factors.
Get most of your carbohydrates from fruits and vegetables. This not only provides your body with a whole host of essential phytonutrients, but the increased fiber is essential for the health of your gut microbiome, which changes during the pausal years.
Decrease sugar and carbohydrate intake and consider eating carbs earlier in the day when your body is more insulin-sensitive.
Avoid ultra-processed foods - research shows that people who eat ultra-processed foods eat an average of 500 calories more per day than those who do not.
Reduce alcohol, which is typically loaded with sugar and empty calories, and tends to trigger late-night snacking and eating, further contributing to weight gain.
Reduce exposure to toxins and endocrine-disrupting chemicals, many of which are obesogens and cause weight gain.
Ensure you get consistent, high-quality sleep – Research shows that women who sleep less consume more calories and crave high-energy (i.e., high-calorie, not-so-nutrient-dense) foods. Lack of sleep and altered circadian rhythmicity impact our appetite hormones, ghrelin (our hunger hormone), and leptin (our satiety hormone), and affect our brain's control and reward center. This tends to lead to unhealthier food choices and an increase in our daily energy intake (i.e., we need more food to feel satisfied).[4]
Exercise and movement
Resistance training provides the most effective, low-cost means by which to prevent muscle loss, improve body composition, improve blood flow, improve total body strength, endurance, and posture, and positively impact multiple aspects of overall health.[5]
For women new to strength training, it is important to start with weights that are manageable. Moving straight to heavy weights when your body is not yet ready can lead to injuries.
Ideally, you will train to lift heavier weights than your body is currently adapted to. The idea is to work to muscle failure so that the last couple of reps should be challenging.
Aim for strength training 2-3 days per week.
Lifting heavier weights or progressive overload is the only way to increase stress on the bone, which helps with bone architecture, bone turnover, increasing/preserving bone density, and decreasing bone loss.
Resistance training also improves stability around the joints, ultimately decreasing joint pain.
HIIT (high-intensity interval training) is highly beneficial to improving body composition, decreasing visceral fat and overall body fat, improving insulin resistance, improving lean muscle mass, strengthening and increasing mitochondria (the energy factories in our cells)[6], and improving neuromuscular stimulation (fast-twitch fiber action ~strong, fast contractions, which are the first to go as we age).[7],[8]
HIIT should not exceed 30 minutes.
High-intensity interval training should ideally be 20-90 seconds of effort with less intense recovery (heart rate doesn’t fully come back down) in between spurts of really hard anaerobic work.
Examples include Tabata style ~ 20 seconds on, 10 seconds off, or 20 seconds on using maximum effort, with 2-4 minutes of moderate, less-intense recovery.
Sprint interval training (SIT), a specific type of HIIT, involves short sprints (i.e., 4 seconds of intense exercise followed by 56 seconds of rest, 8 seconds of intense exercise followed by 52 seconds of rest, etc.) running or on a bike/stationary bike can help to reduce unwanted visceral fat and increase lean muscle mass.[9] This type of exercise helps to burn more fat while we are not exercising too.
HIIT (SIT) is highly effective for improving insulin sensitivity because it requires carbohydrates, so it pulls a lot of glucose from our bloodstream, which decreases our blood sugar. Our body must replenish our muscle and liver glycogen stores with carbohydrates so we burn more fat while we are at rest. HIIT (SIT) helps our body access more of our GLUT 4 proteins (our superstar glucose transporters), allowing more glucose into our cells. This lowers our blood glucose levels and allows our body to burn fat even when not exercising. Win-win!
It is critically important that HIIT is followed up with a substantial dose of protein, ideally 40 grams of protein, along with some high-quality carbohydrates, which helps decrease cortisol quickly, decrease fat storage, and lower inflammation.
Moderate steady-state cardio exercise does not confer the same benefits as HIIT in body composition changes, insulin sensitivity, etc. It increases cortisol and allows it to hang around longer, something we don’t want in our highly stressed women. Elevated cortisol can increase inflammation, body fat, and muscle breakdown.
Plyometrics helps counter the effects of age-related deterioration that often lead to the progressive decline of neuromuscular function, increased risk of falls and fractures, impaired functional performance, and loss of independence.[10]
Plyometrics involves fast and explosive movements ~ think skipping, jumping, burpees, jumping on a trampoline, etc.
Start small and easy, working your way up over time.
If you suffer from pelvic floor issues/incontinence when doing these movements, seeking help from a pelvic floor specialist is essential.
Try not to sit for longer than 20 minutes at a time. Break up long periods of sitting with brief stretching or walking around the office, home, or outside. It doesn't have to be long or intense; getting up and moving matters.
Optimal recovery is critical. The bulk of the changes in our body and our fitness adaptations happen during recovery and when we sleep, so be sure to incorporate recovery into your routine. Recovery doesn’t mean “sitting all day,” but instead focusing on an easy, more leisurely type of functional movement (i.e., walking, hiking, swimming, leisurely cycling, yoga, Pilates, etc.).
Supplements
MCT oil (medium-chain triglycerides) 6 grams per day may improve muscle mass.[11]
Probiotics, specifically Lactobacillus rhamnosus, support weight loss.[12]
Leucine is the most anabolic (building) of all amino acids and supports the maintenance of muscle mass.[13], [14]
Research has shown that protein with amino acids is the most effective way to improve muscle mass in older adults.[15] Consider incorporating fermented branched-chain amino acids (BCAAs) into your routine.
Daily vitamin D supplementation appears to improve muscle function and body composition but has no significant effect on muscle strength.[16]
Hormone replacement therapy
Estrogen replacement therapy improves body composition in women in menopause. Body composition changes can take time after initiating estrogen replacement therapy, from 6-12 months, depending on food and lifestyle factors and where a woman is in her pausal journey.[17] While endogenous estrogen plays a huge role in building muscle, estrogen in HRT will not pack the same punch as the estrogen we make. Exercise is a huge factor in helping to maintain muscle.
Progesterone replacement therapy can help improve bone turnover and is used with estrogen replacement therapy, which can help improve blood sugar control, decrease fat storage, and more.
Testosterone replacement. Since one of testosterone's primary roles is an insulin and glucose modulator (i.e., it's critical for maintaining blood sugar balance), losing our testosterone increases our risk for developing insulin resistance, which sets us up for pre-diabetes diabetes and weight gain. There are testosterone receptors all over the body, so replacing lost testosterone can be a game-changer for women.
Warning: As always, check with your physician or licensed healthcare practitioner before trying any new supplements.
Important medical disclaimer
The contents of this blog are for informational purposes only and are not a substitute for professional medical advice. None of the recommendations, suggestions, or written information provided is intended to replace a one-on-one relationship with a qualified health care professional. The information presented is not intended to diagnose, treat, cure, or prevent any disease but rather as a sharing of knowledge and information from the research and experience of Jill Chmielewski, RN, BSN. You are encouraged to make your own health care decisions based on your research and partnership with a qualified healthcare professional of your choosing.
References
[1] Xie, Wen-Qing et al. “Caloric restriction: implications for sarcopenia and potential mechanisms.” Aging vol. 12,23 (2020): 24441-24452. doi:10.18632/aging.103987
[2] Symons, T Brock et al. “A moderate serving of high-quality protein maximally stimulates skeletal muscle protein synthesis in young and elderly subjects.” Journal of the American Dietetic Association vol. 109,9 (2009): 1582-6. doi:10.1016/j.jada.2009.06.369
[3] Verlaan, Sjors et al. “Sufficient levels of 25-hydroxyvitamin D and protein intake required to increase muscle mass in sarcopenic older adults - The PROVIDE study.” Clinical nutrition (Edinburgh, Scotland) vol. 37,2 (2018): 551-557. doi:10.1016/j.clnu.2017.01.005
[4] Chaput, Jean-Philippe et al. “The role of insufficient sleep and circadian misalignment in obesity.” Nature reviews. Endocrinology vol. 19,2 (2023): 82-97. doi:10.1038/s41574-022-00747-7.
[5] McKendry, James et al. “Nutritional Supplements to Support Resistance Exercise in Countering the Sarcopenia of Aging.” Nutrients vol. 12,7 2057. 10 Jul. 2020, doi:10.3390/nu12072057
[6] Yeager, S. “Build More Muscle Without Weights.” https://www.feistymenopause.com/blog/buildmuscle. Last accessed September 28, 2023.
[7] Dupuit, Marine et al. “Effect of high intensity interval training on body composition in women before and after menopause: a meta-analysis.” Experimental physiology vol. 105,9 (2020): 1470-1490. doi:10.1113/EP088654
[8] Maillard, Florie et al. “Effect of High-Intensity Interval Training on Total, Abdominal and Visceral Fat Mass: A Meta-Analysis.” Sports medicine (Auckland, N.Z.) vol. 48,2 (2018): 269-288. doi:10.1007/s40279-017-0807-y
[9] Allen, Jakob et al. “Inertial Load Power Cycling Training Increases Muscle Mass and Aerobic Power in Older Adults.” Medicine & Science in Sports & Exercise 53(6):p 1188-1193, (June 2021). doi: 10.1249/MSS.0000000000002588.
[10] Vetrovsky, Tomas et al. “The Efficacy and Safety of Lower-Limb Plyometric Training in Older Adults: A Systematic Review.” Sports medicine (Auckland, N.Z.) vol. 49,1 (2019): 113-131. doi:10.1007/s40279-018-1018-x
[11] Abe, Sakiko et al. “Medium-chain triglycerides (8:0 and 10:0) are promising nutrients for sarcopenia: a randomized controlled trial.” The American journal of clinical nutrition vol. 110,3 (2019): 652-665. doi:10.1093/ajcn/nqz138
[12] Sanchez, Marina et al. “Effect of Lactobacillus rhamnosus CGMCC1.3724 supplementation on weight loss and maintenance in obese men and women.” The British journal of nutrition vol. 111,8 (2014): 1507-19. doi:10.1017/S0007114513003875
[13] Martínez-Arnau, Francisco M et al. “Effects of Leucine Administration in Sarcopenia: A Randomized and Placebo-controlled Clinical Trial.” Nutrients vol. 12,4 932. 27 Mar. 2020, doi:10.3390/nu12040932
[14] Gielen, Evelien et al. “Nutritional interventions to improve muscle mass, muscle strength, and physical performance in older people: an umbrella review of systematic reviews and meta-analyses.” Nutrition reviews vol. 79,2 (2021): 121-147. doi:10.1093/nutrit/nuaa011
[15] Martin-Cantero, Aitana et al. “Factors influencing the efficacy of nutritional interventions on muscle mass in older adults: a systematic review and meta-analysis.” Nutrition reviews vol. 79,3 (2021): 315-330. doi:10.1093/nutrit/nuaa064
[16] Abiri B., Dehghani M., Vafa M. “Effect of Vitamin D Supplementation on Muscle Strength, Muscle Function, and Body Composition in Vitamin D-Deficient Middle-Aged Women.” In: Guest P. (eds) Clinical and Preclinical Models for Maximizing Healthspan. Methods in Molecular Biology, vol 2138 (2020). Humana, New York, NY. https://doi.org/10.1007/978-1-0716-0471-7_25
[17] Robertson, Jordan. “The ABCs of HRT.” The Confident Clinician Club lecture series. Last accessed June 7, 2021.