You’re standing in the kitchen, and something’s off. Not wrong, exactly. Just off. You’re eating the same breakfast you’ve eaten for years. You went to your usual class this morning. Nothing about your routine has changed. And yet your jeans fit differently than they did five years ago, and no amount of “just eat less, move more” seems to change things.
If that sounds familiar, here’s what’s going on: your body is running on different biology than it was a decade ago. The strategies that worked on your 30-year-old hormones aren’t guaranteed to work now that their levels and fluctuations are in a transition phase and are shifting.
Dr. Ariane Ouellet-Decoste, Coral’s medical director, and Linda Franco, Coral’s director of patient care, presented part two of our Midlife Health Masterclass series to break down what’s driving these changes. Sleep, stress, insulin, and muscle mass work as one connected system, not four separate concerns. Here’s how they feed into each other, and what the research says you can do along the way to better support your body and your health.
This article covers the highlights, but there’s a lot more nuance in the room. Watch the full masterclass recording with Dr. Ariane and Linda.
[Watch the full masterclass recording →]
It all starts with sleep
Poor sleep dials up hunger and cravings and dials down insulin sensitivity, which sets the stage for the next few items on this list.
Sleep affects two hormones you’ve probably never thought about: ghrelin and leptin, your body’s hunger and fullness switches. When sleep is short or low quality, ghrelin goes up and leptin goes down1. It means you feel hungrier, and less full once you’ve eaten, with cravings that tend to point toward processed carbs and sugar specifically. A lack of sleep also lowers insulin sensitivity, which we’ll come back to shortly. During perimenopause and menopause, hormonal shifts affect sleep quality directly, and disrupted sleep changes how your body handles those same hormones in return. Simply put, poor sleep and hormonal changes feed each other.
Does scrolling on your phone before bed really matter?
In the masterclass, 91% of attendees said they’d looked at their phone within 15–20 minutes of going to bed the night before. Screen light signals to your brain that it’s daytime, which suppresses melatonin, the hormone that helps regulate when your body winds down. A blue light screen filter or more distance between your phone and your pillow can make a real difference.
A couple of other tips worth knowing about
Getting outside or near a window shortly after waking helps set your hormone rhythm for the day, and if you’re someone who metabolizes caffeine slowly (like more than half the population), an earlier cutoff (before midday) will greatly help reduce how much it interferes with sleep later on.
Alcohol can help you fall asleep faster and make you feel like you are in a deep sleep, but it disrupts the deep and REM sleep your body needs to recover overnight. Even a single glass of wine can trigger this. It’s worth paying attention and becoming aware of how you sleep on nights you drink versus nights you don’t.
If sleeping separately from a partner improves your sleep quality, research actually links that to better intimacy. That’s useful information about your body, and nothing to feel guilty about.
All of this matters more here than it did at 30, because vasomotor symptoms like hot flashes and night sweats are one of the most common reasons sleep gets interrupted during this transition. And interrupted sleep is exactly what keeps the next system in this list switched on.
Why your nervous system stays switched on
When your body’s stress-response system doesn’t fully power down, it starts storing fat in your midsection, and that effect gets more pronounced with age, which is the next link from the sleep loop above.
Your nervous system has a built-in alarm system called the HPA axis (hypothalamic-pituitary-adrenal axis). When your brain detects a stressor like an upcoming work deadline, a dip in blood sugar or a really bad night’s sleep, it sends a signal down a chain that ends with your adrenal glands releasing cortisol. In the short term, this is exactly what it’s supposed to do: sharpen your focus, give you an energy boost, activate the “fight or flight” response you need to act in a moment of pressure. The problem shows up when it never fully switches off. Chronically elevated cortisol increases visceral fat, the fat that sits deep around your organs and midsection and it is this specific type of fat that increases inflammation and the risk of cardiovascular diseases.
This is the part of the conversation where “cortisol belly” often comes up, so it’s worth addressing up front.
Is “cortisol belly” real?
There’s a real mechanism here, but social media overstates it. In Cushing’s syndrome, where a tumor or long-term steroid medication (like prednisone) drives dangerously high levels of cortisol, researchers see up to 45% more fat around the organs But that’s not what’s happening from ordinary daily stress.
What is true, and more gradual, is that chronic stress does shift where your body stores fat over time, which is known as allostatic load. Allostatic load is the cumulative biological wear and tear the body undergoes when exposed to prolonged stress. Chronically elevated cortisol levels are one of the main triggers and drivers of this wear and tear, as the hormone keeps the body’s systems in a permanent state of alert, causing metabolic, immune, and cardiovascular damage over time.One study following 2,000 women in midlife found this load increasing roughly 3% with each follow-up visit2.
The tool with the strongest evidence for interrupting this loop is called cardiac coherence: a breathing pattern, inhale for five seconds and exhale for five seconds, that activates your vagus nerve, the direct line to your “rest and digest”3 system. Five minutes, two to three times a day, has been shown to change how your nervous system handles stress for years afterward. Nidra Yoga and tai chi have similar backing.
Isn’t high-intensity interval training bad for cortisol?
It depends on the time and on your needs. If you’re already under a heavy stress load, HIIT activates a system that’s already overworked, and something gentler may serve you better that day. And true HIIT needs real recovery between intervals. An hour of sustained high intensity isn’t HIIT, it’s just prolonged strain. A shorter session with real recovery built in tends to work better for the body during this transition.
How that cortisol loop shows up as insulin resistance
As estrogen fluctuates and declines during perimenopause, insulin sensitivity tends to decrease. The same stress-and-sleep disruption above is one of the reasons identical habits stop producing the results they used to.
Insulin’s job is to manage how your body uses and stores energy: when you eat, it moves that energy into your muscles for use or into storage if there’s more than you need. As estrogen becomes unstable and then declines through this transition, insulin sensitivity can decrease, so the same food and the same workout can affect your body differently than they did before. Left unaddressed, this is linked to inflammation and long-term risk for things like cardiovascular disease and some cancers. It also currently isn’t well screened in the healthcare system, largely because traditionnal medecine tends to be reactive rather than proactive and tends to detect illnesses that are treatable with medication. Insulin resistance mainly gets treated by lifestyle changes. Common tests screen for pre-diabetes and diabetes, both of which only show up years after insulin resistance has already begun. If this interests you, it’s worth asking your care provider how you can screen for insulin resistance.
On the food side, the point isn’t restriction. Whole, minimally processed food reduces inflammatory load, while protein needs may increase with time. A rough target of 1.2 grams per kilogram of body weight per day, spread across meals starting with breakfast, supports steadier hunger hormones and helps to maintain a stable level of energy throughout the day. A typical high-carb, low-protein North American breakfast (a bowl of sugary cereal, a bagel and a juice) works against what you need to feel good and age healthy.
Does intermittent fasting help in midlife?
It depends (again!) on your body, your metabolism and your needs. It may help some people manage insulin resistance and high blood pressure , but a shorter eating window means being more deliberate about protein and nutrients within it, and it may not suit you if it adds stress to your morning or conflicts with training.
The piece you can most directly change: muscle
Muscle is your body’s largest glucose-clearing tissue, so the muscle loss that begins in your 30s and speeds up at menopause is a direct extension of the insulin resistance above. Of everything we listed so far, this is the one factor you have the most control over.
Think of muscle as a sponge that absorbs glucose out of your bloodstream after you eat. That sponge naturally shrinks starting around age 30 or 40 (roughly 0.5 to 1% of muscle mass per year), and the rate tends to increase through menopause as estrogen’s role in protecting muscle protein, and testosterone’s role in muscle size and strength, both decline. Less muscle means less capacity to clear glucose, which feeds directly back into the insulin resistance loop above.
This factor is also the one that responds fastest to what you do about it. Resistance training two to three times a week has a measurable impact on muscle mass. Short HIIT sessions add another layer: as little as 20 minutes, once or twice a week, with real recovery built in, targeting visceral fat specifically.
Someone in the Masterclass audience said the quiet part out loud: they hate cardio and wanted to know if they could skip it… don’t we all? But unfortunately, for most people, cardio is still beneficial, though it doesn’t need to be intense. A brisk walk raises your heart rate enough to matter, and staying in “zone 2” (a pace where you can still hold a conversation) for longer sessions can be just as effective for body composition as harder workouts. Daily movement, aiming for 7,000–10,000 steps, supports the same systems.
One low-effort tip from the masterclass: 20 to 30 squats and 20 to 30 calf raises in a 30 to 40 minute window after a meal helps your muscles pull glucose out of your bloodstream right when it matters most, and tends to take the edge off that overly-full, bloated feeling too. It looks a little ridiculous doing it in your kitchen, especially at work, but nobody’s judging. Well… maybe George from accounting.
Where medication fits into this same system
Menopause hormone therapy (MHT, previously called HRT) doesn’t cause weight gain or weight loss. The research data doesn’t support either claim. As a secondary benefits, what it does do is help reduce visceral fat accumulation, support the hormone balance behind sleep, and help your body rebuild muscle protein, which is why it works alongside the sleep, nervous system, and muscle strategies above rather than replacing them4. It’s also a different formulation and dose than birth control pills many people took decades ago, so past experience with those doesn’t predict how MHT will affect you. MHT isn’t the right fit for everyone, and like any prescription therapy it carries its own risks and considerations. Your care team can help you weigh those against your own health history.
GLP-1 medications (like Ozempic) are a newer class of prescription treatment that a prescriber may discuss as part of weight management. There’s one consideration worth knowing about, tied to the muscle section above: a meaningful portion of the weight lost on these medications can be muscle rather than fat5. That’s why pairing a GLP-1 with resistance training is essential.
What this looks like for you, including expected outcomes, is worth discussing directly with a care provider. Decisions here are personal but it’s important to look at progress from a body composition lens versus numbers on a scale.
Where to start
If one part of this resonated more than the rest, whether that’s sleep, your nervous system, food, or muscle, that’s a reasonable place to start, since progress in any one area tends to ease the others. Working on your breathing for a few weeks, for example, can improve sleep and eating patterns too, without you touching either directly.
If you’d rather work through this on paper, we built a companion checklist for this masterclass, with space to map out where you want to start.
Listen to your body along the way. If a workout plan causes pain or triggers more hot flashes, that’s information, not a failure. The plan that works is usually just the one you can keep doing.
If you want support figuring out where your biology is at right now, book a call with a Coral care coordinator to see if there’s a care plan that would be the right fit for you.
Disclaimer: The information provided here is for informational purposes only. It is not intended as medical advice. Always consult with your doctor or healthcare provider to determine what is best for your individual health needs.
While we use the word “women” for simplicity, we recognize that menopause and perimenopause can affect people of many gender identities. Our goal is to support everyone who experiences these changes.
Sources:
- van Egmond LT, Meth EMS, Engström J, et al. Effects of acute sleep loss on leptin, ghrelin, and adiponectin in adults with healthy weight and obesity: A laboratory study. Obesity (Silver Spring). 2023; 31(3): 635-641. doi:10.1002/oby.23616 ↩︎
- Yufan Guan, Jie Shen, Juan Lu, Bernard F. Fuemmeler, Lisa S. Shock, Hua Zhao, Allostatic load score and lifestyle factors in the SWAN cohort: A longitudinal analysis,Public Health in Practice, Volume 9,2025, 100590, ISSN 2666-5352, https://doi.org/10.1016/j.puhip.2025.100590. ↩︎
- Laborde, S., Mosley, E., & Thayer, J. F. (2017). Heart Rate Variability and Cardiac Vagal Tone in Psychophysiological Research – Recommendations for Experiment Planning, Data Analysis, and Data Reporting. Frontiers in psychology, 8, 213. https://doi.org/10.3389/fpsyg.2017.00213 ↩︎
- Georgios E Papadakis, Didier Hans, Elena Gonzalez Rodriguez, Peter Vollenweider, Gerard Waeber, Pedro Marques-Vidal, Olivier Lamy, Menopausal Hormone Therapy Is Associated With Reduced Total and Visceral Adiposity: The OsteoLaus Cohort, The Journal of Clinical Endocrinology & Metabolism, Volume 103, Issue 5, May 2018, Pages 1948–1957, https://doi.org/10.1210/jc.2017-02449 ↩︎
- Bikou, A., Dermiki-Gkana, F., Penteris, M., Constantinides, T. K., & Kontogiorgis, C. (2024). A systematic review of the effect of semaglutide on lean mass: insights from clinical trials. Expert opinion on pharmacotherapy, 25(5), 611–619. https://doi.org/10.1080/14656566.2024.2343092 ↩︎
