Metabolism, muscle mass, and perimenopausal weight gain
A common concern that my patients share with me is that they feel that their metabolism has changed, and they suspect it's related to their hormones shifting as they go through peri menopause and menopause. Another factor impacting their change in body composition is that they're aging, and may be experiencing sarcopenia.
What the heck is Sarcopenia?
Sarcopenia is age related lean tissue loss. It refers to a decline of skeletal muscle mass and function that is known to lead to physical frailty and falls, osteoporosis, metabolic syndromes, and ultimately earlier death.
Sarcopenic obesity describes the change in body shape that happens, even if the weight on the scale hasn't. It's the complex metabolic process as we age of losing lean muscle and gaining fat mass. We are not metabolically the same in our 40s as we were in our 20s; we lose a measurable percentage of muscle mass each year after 30 years of age - unless we have an intentional strategy to prevent that.
So, what do we do about it?
There are no approved drugs for sarcopenia; just diet and exercise!
This is within our control, and the earlier we start being intentional, the better we will age.
Protein metabolism and Requirements change as we age.
The first thing we need to do to preserve metabolism boosting lean muscle tissue is to understand that we need more protein to do the same work. As people age, they don't digest protein as well; they aren't absorbing as much from their food, and they aren't synthesizing it in their bodies as well as they did in their youth.
Aim to consume 1 - 1.5 g of protein/kg of your weight (weight in lb/2.2). Someone weighing 150 lb, should consume 100 g of protein per day - around 30 g/meal.
Leucine, creatinine, and other high-quality amino acid building blocks of protein appear to compound beneficial aspects of resistance training in older patients.
The Importance of Combination Exercise
Aerobic exercise provides at least a partial solution to sarcopenia as it ameliorates mitochondria-derived problems, and resistance exercise strengthens muscle mass and function. Combinations of these exercise types provide the benefits of both - the most beneficial means of combating age-related sarcopenia.
Strength & Resisting Training
A 2021 review study of the Effects of resistance training in healthy older people with sarcopenia found significant decreases in Body Fat Mass (BFM) in resistance training groups compared to controls.
Muscle mass significantly increased, with the greatest increase of muscle mass observed when the resistance training was completed more than 3 times per week for at least 12 weeks.
How declining Estrogen at Menopause Causes Weight Gain
Loss of estrogen at menopause changes where we put weight. Higher levels of estrogen encouraged fat accumulation in the booty, and when they decline our bodies accumulate fat instead around our middle.
Hormones also influence how we feel which then impacts how much we move and what we eat.
Sex hormones influence drivers of food intake such as circadian rhythm, emotions, psychological state and stress.
Studies conclude that menopause doesn't make women gain weight, but the symptoms of hormone imbalances that can accompany menopause may result in women eating more and moving less.
Exercise is the only way to increase energy expenditure. So what are your barriers to exercising?
Are you fatigued? We have to address why you're fatigued, so that you have the energy to exercise.
Are you having trouble falling or staying asleep? Then we need to rebalance your circadian rhythms.
How is your mood? If you're depressed, we need to assemble a health care team to work on that with you so that you can feel motivated to exercise.
Potential Lab Testing to Identify Obstacles to a Healthy Body Composition:
Fasting Glucose, Insulin and HOMA-IR
Cholesterol panel
Liver Enzymes (and/or ultrasound) for fatty liver disease (NAFLD)
Thyroid Panel (TSH, T4, T3, rT3, anti-TPO, anti-TG)
Serum hormones/BBT to assess ovulation and menopause status
PCOS Screening: LH/FSH ratio, AMH
Serum androgens (total & free testosterone)
SHBG
Vitamin D
Ferritin
CBC with platelet count
Long Term Maintenance of Healthy Body Weight: What the Research Tells Us
The Look AHEAD study on diabetes prevention: after 8 years of follow up, 65% had maintained their initial weight loss of ~5% bodyweight, which is the amount needed to prevent diseases like diabetes. The key to their success was frequent, group meetings.
In the Lean Habits Study, researchers identified behavioural characteristics that influenced how successful participants were at maintaining a healthy weight:
Flexible vs. rigid dietary control meant more success
Meal regularity: consistent timing of breakfast lunch and dinner
Eating Behaviours: those who ate while working did worse, while those who ate with family did better
Food choices
Restriction of food quantity
Greater physical activity and less screen time
Stress coping
Key Take Aways
Address underlying causes of hormone imbalance, fatigue, or metabolic dysfunction to optimize body composition.
Increase protein consumption to achieve the requirements of someone with your body weight.
Combine aerobic and resistance exercise 3 times per week for 3 months to see the benefit, and maintain long term to age healthfully.
The information in this article is not intended to diagnose, treat, cure, or prevent any disease. It is not intended to replace any recommendations or relationship with your physician. Please review linked references for scientific support.