Earlier this month, we discussed the relative insulin resistance of midlife in my post Understanding and Conquering the Relative Insulin Resistance of Midlife. We talked about how circulating estrogen and the estrogen receptors in muscle tissue change and how this leads to lower efficiency in managing blood sugar relative to our younger reproductive years. This leaves a greater excess of sugar in the bloodstream, unused by the tissues, to be stored as fat.
But that stubborn “belly fat” of midlife isn’t ALL about excess sugar, less estrogen, or calories in / calories out. Another key player in the belly fat equation is our friend (yes, our FRIEND) Cortisol - aka the “Stress response system”.
Biological females are programmed by nature to be highly sensitive to energy availability. An adequate fat mass percentage is required for the onset of puberty. One of the most reliable signs of persistent low energy availability (LEA) during our reproductive years is the loss of regular menstrual cycles. The mechanisms by which energy availability influences female physiology include direct communication with the hypothalamus, which is the command center for not just the menstrual cycle, but also the stress response system.
So what happens when we become menopausal and the menstrual cycle is no longer in the equation? The stress response system becomes front and center as a key responder to energy availability and storage in the body. How is energy stored in the body? As glycogen in the skeletal muscles and liver and as … you guessed it… FAT.
There has been a lot of buzz over the hormone, “Cortisol”. I blogged about this in a recent post, Stop Demonizing Cortisol!. Cortisol is just one of MANY hormones and mediators of the stress response system. As circulating estrogen declines and menstrual cycles become less frequent, we lose a key “buffer” of resiliency in stress response activation and recovery while still maintaining that same sensitivity to energy availability. So when the body senses low energy availability through mediators such as leptin, ghrelin, and kisspeptin, the “alarm” is sounded to alert the stress response system to conserve energy by “hanging on” to fat storage, increasing the sensation of fatigue to slow the body down, if prolonged, thyroid function may be suppressed, among other adaptations. Brain fog and sometimes even depressive symptoms may also set in.
Key sensors of fuel and nutrient availability throughout the body (Kisspeptin, Leptin, Ghrelin) communicate with the stress response system. When fuel availability is persistently low, the stress response system is activated. When fuel and nutrients are adequate, the stress response system is in balance.
Here is how it often unfolds: We start down the midlife journey of perimenopause and notice a change in body composition - sometimes dramatically in a short period of time! Our “knee-jerk” reaction is to “eat less and train more”. Then we discover that what we used to do to lose that quick 5 - 10 lbs is no longer working. So we eat even less and train even more - and so the vicious cycle begins - the stress response system now thinks there is a worldwide famine and the body holds on to every last fat cell for dear life, dials down a whole bunch of bodily processes and then we feel like crap - and defeated. Sound familiar?
So what do we do now? This is where we roll up our sleeves and start working WITH our physiology - not against it. First, energy balance needs to be restored, but with a strategy that works with our perimenopausal/menopausal physiology:
Pay closer attention to protein intake (0.7-1g of protein per pound of body weight).
Ensure adequate total energy intake. According to the International Olympic Committee (IOC) 2023 Consensus Statement on REDs, a study was cited where 45 kcal/kg of fat-free mass (FFM)/day represents energy intake that supports maintenance and growth. So, for a 135 lb woman with 20% body fat (60 kg x 20% = 48 kg FFM), this equates to 2,160 kcal/day.
It’s important to note that these are just guidelines and that each athlete’s goals and circumstances need to be considered when optimizing total energy requirements.
Minimize refined sugar intake and focus more on high-quality carbohydrate sources. As we mentioned previously, insulin does not work as efficiently as it once did.
Adequate carbohydrate intake - According to the International Olympic Committee (IOC) 2023 Consensus Statement on REDs, inadequate carbohydrate intake is a major contributor to a low energy availability (LEA) state and Relative Energy Deficiency in sport (REDs). What defines “adequate” varies with the type and volume of physical activity, however, the “danger zone” appears to be below 3g carbohydrate (CHO)/kg body weight/day. This threshold to the “danger zone” equates to 160g of carbohydrate for a 60 kg (135 lb)woman - and this is the lower end of carbohydrate need! For endurance and other competitive athletes, this need can exceed 7g CHO/kg/day.
Again, it’s important to note that these numbers are just a guide and that each athlete’s circumstances need to be taken into account when optimizing carbohydrate intake.
Avoid fasting for more than 12 hours (overnight from dinner to breakfast). Dr. Stacy Sims, renowned exercise physiologist, and nutrition scientist has blogged a lot on this topic stating that prolonged or intermittent fasting provides no potential benefits and potential for harm, particularly in active midlife women without obesity or metabolic disturbance.
Avoid training fasted - Many people just don’t like to eat in the morning before training, but having no fuel on board after an overnight fast and then challenging the body with training will look like a “five-alarm fire” to your stress response system. Even consuming just a little something before training after an overnight fast will go a long way in reassuring your stress response system that there is fuel available to support this activity. A half of an apple with some nut butter or hard-boiled egg is sufficient to get you started. Whole food shakes that you prepare yourself (free of any refined sugar) are also a great option.
Nutrient timing - Put simply, the body wants fuel when it needs it, and the times of increased need are before, during, and after training. Ensuring that there is fuel available within 1 hour of a workout, during workouts that are > 1 hour in length, and within an hour after training will, again, reassure the stress response system that fuel is available.
Mother Nature has programmed within females an incredible capacity to adapt to physical training and sport, as evidenced by our innate ability to adapt to the profound physical demands of pregnancy across the entire spectrum of poor to good health.
But to unlock this potential, we need to work WITH our physiology and not fight AGAINST it. By understanding how the physiology of the menopause transition works, we are better equipped to thrive within these changes and live our healthiest lives full of vitality into our 8th, 9th, and even 10th decades!
Housekeeping…..
I am so thrilled to announce the launch of my latest course contribution, Navigate Menopause with my friends and colleagues at Feisty! This AWESOME course dispels the confusion and busts the myths surrounding menopause and gives you the tools you need to empower yourself to take your menopause experience into your own hands.
ENROLLMENT STARTS MONDAY JANUARY 22nd! Click HERE to sign up! Space is limited and will be closed once course capacity has been reached.