This is Part Two of the Weight Loss & Insulin Series; click here to access part 1

In Part One I walked you through how chronically elevated insulin locks the door on fat burning — and why so many women in midlife are eating well, exercising consistently, and still watching the scale not move. If you haven't read it yet, start there. This part builds directly on that foundation, and is the part most fitness coaches and nutritionists leave out.

The second major hormonal driver of insulin dysregulation that almost no one talks about is cortisol — because it's also an insulin driver, and ever more prevalent in perimenopause and beyond. Let's unpack why you need to also regulate your cortisol in order to lose weight in midlife.

First, you need to understand what's happening to your stress response in midlife.

Stay with me, this part's kinda geeky but I promise, once you understand all this, you know WHAT to do and WHY. So, estrogen has a protective effect on insulin sensitivity — we covered that in Part One. But estrogen also directly modulates your stress response. It acts on the HPA axis — the hypothalamic-pituitary-adrenal system that controls how much cortisol you produce — and it keeps that system calibrated. Estrogen essentially puts a ceiling on how hard your cortisol response fires.

When estrogen starts declining in perimenopause, that ceiling lifts. Your HPA axis becomes dysregulated — more reactive, less able to self-correct. What this means in practice is that stressors that your body used to handle fluidly now trigger a larger cortisol spike, and that spike takes longer to come back down. So, the same traffic jam, the same difficult conversation, the same bad night of sleep that you navigated reasonably well in your thirties: now produces a measurably bigger hormonal response than it used to. Think about it: have you recently felt stressed and anxious over something that used to be no big deal? And did you wind up having high-cortisol consequences? For me, it's travel. I used to hop on long-haul flights, no problem! I'd sleep through the entire flight and arrive, ready for adventure. These days, I can't sleep on the flight, and even though I'm excited and wired upon arrival, it usually cues a migraine. Vacation or work, like it or not, that's my estrogen-deprived HPA axis reacting to high-cortisol travel moments:  unfamiliar environments, different time zones, climate changes, air turbulence, delays, all of it. 

There's more. Estrogen also supports serotonin production, and serotonin helps regulate cortisol. Less estrogen means less serotonin buffering, which means the HPA axis is even less regulated. And progesterone — which also declines in this phase, often before estrogen does — has a natural calming effect on the nervous system through its conversion to allopregnanolone, which acts on GABA receptors. As progesterone drops, that calming buffer disappears too. So you're losing estrogen's moderating effect on cortisol at the same time you're losing progesterone's calming effect on the nervous system. The result is a stress response system that is genuinely more sensitive, more reactive, and slower to recover than it was a decade ago — through no fault of your own.

This is why the woman who considers herself pretty low-stress finds herself in perimenopause suddenly feeling wired, anxious, overwhelmed, and unable to wind down at night. (To say nothing about us Type-A personality types). Because of shifting hormones, her hormonal buffer around stress got thinner. 

So what's cortisol, and why does it matter for your weight?

Cortisol is a hormone produced by your adrenal glands any time your body perceives stress — physical or emotional. In the short term it's brilliant. It mobilizes glucose from stored glycogen and fat tissue, delivers rapid energy to your muscles and brain, sharpens your focus, preparing you for a response: fight or flight. 

Where it becomes a problem is when that stress response never fully switches off. And in midlife, for so many of us, it doesn't. In midlife we're often facing financial pressures, relationship strain, scheduling havoc with family members, work overload, poor sleep, under-eating, over-exercising, and the hormonal volatility of perimenopause itself . All of this keeps cortisol running at a low, chronic simmer. And a body running on sustained cortisol is a body in a permanent state of metabolic emergency.

What does cortisol actually do to your insulin?

Every time cortisol is released, it signals your liver to pump out more glucose. At the same time it instructs your muscle and fat cells to become temporarily resistant to insulin — essentially telling them: stay alert, keep that glucose circulating, we might need it.

Here's where it gets really important, and it ties in to what we talked about in Part 1. Your pancreas sees that blood glucose rising and responds the only way it knows how: it releases insulin. Not because you ate or you're on a cheat day; your stress hormones created a blood sugar spike, and now insulin has to manage it.

And as we talked about in Part One — where insulin goes, fat storage follows. Elevated insulin shuts down lipolysis, which is the process by which your fat cells release stored fatty acids to be burned as fuel. You cannot be in fat-burning mode and high-insulin mode at the same time. So cortisol, when it's chronically elevated, becomes an insulin trigger — a fat-storage signal — that has nothing to do with what's on your plate.

And the fat it lays down? It goes straight to your middle.

That abdominal weight gain isn't random. Visceral fat — the deep belly fat that accumulates in this phase — is metabolically active. It produces inflammatory compounds that further impair insulin signaling, which drives more fat storage, which produces more inflammation. Cortisol preferentially deposits fat in this region, which is why chronic stress and midlife weight gain share such a specific and recognizable pattern. And it's why the woman I described earlier — doing everything right, nothing changed — is gaining weight in a place she never used to.

Here's what's critical to know: addressing weight gain in midlife is about regulating insulin, but from different directions: from the food you're eating, the amount of lean mass you have and from the cortisol levels you're trying to manage.

Let me say that again, so it sinks in: for weight loss in midlife to occur, you need to manage your insulin levels. There are a few levers to pull to do this effectively: 1) lower your blood sugar levels by cutting down on insulin-spiking foods like processed foods and sugary treats, stop snacking so your insulin levels have a chance to come down after meals, and move your body after eating to stabilize blood sugar; 2) increase your lean mass by lifting more weights (so you increase your glucose sink); and 3) modulate your stress levels down so you're not spiking insulin. 

This is such a key factor for so many of you, who reach out to me: "I don't understand! I'm doing all the things, lifting weights and eating clean and I can't get the scale to budge." Could it be your cortisol levels and you living in a chronic state of high stress? I encourage you to look there. 

Great. So how do I bring my cortisol down, Juliana?

I'm glad you asked. Let me give you some practical guidance here, because I see a lot of people in this space mentioning the need to "reduce stress" but no one's telling you how. (For what it's worth, this is why I built my soon-launching masterclass. Because getting in shape in midlife isn't a simple calories-in, calories-out approach. You need the whole system to be in harmony, and not many people talk about that interconnectedness). 

Here's what actually works.

1. Limit your stressors as best you can.

We all have stressors we can't manage — the car that cut us off on the highway, the unexpected dentist bill. But there are a lot of stressors we can control and limit. This means we need to audit what's keeping us in an elevated cortisol state and make some big decisions. As an example, I used to love "taking a break from work" by listening to political podcasts. My favorite hosts were oh-so-funny and witty as they would rant about all the political crises of the day, and I'd agree!, rage-walking and shaking my head in sympathy. But on the inside: I was in full sympathetic mode and my cortisol: near stratospheric levels.

Similarly, there are certain family members I love and adore, but these days I keep them at a distance because they are high-cortisol triggers for me. I limit visits to 48 hours max, and I've gotten very good at the strategic 15-minute phone calls twice a month "to keep in touch," even as I'm protecting my nervous system. If you're dealing with high cortisol, consider what inputs might need an audit at this phase in life: maybe it's someone you follow on Instagram that makes you feel badly about yourself, or TV shows that are gripping but triggering, or people IRL who push your buttons. You don't need to cut out everything, but doing a careful audit and seeing what you can limit is golden. 

2. After a stressful situation, move your body. 

Whatever that stress-inducing situation was that sent your nervous system into overdrive — that tense meeting, an argument that enraged you — your blood glucose just spiked. Cortisol got activated and it signaled your liver to flood your bloodstream with glucose to prepare you to fight or flee. But you didn't. You kept sitting in the meeting. Or you stewed over that conversation. And that glucose is still circulating, waiting for insulin to come clean it up.

But stay with me, because our muscles contain something called GLUT4 transporters — glucose transporters that move to the surface of muscle cells during physical activity and they pull glucose directly out of your bloodstream. Without insulin. Muscle contraction is one of the very few mechanisms in your body that clears blood glucose independently of insulin — meaning you can interrupt the cortisol-glucose-insulin cascade before it even completes. WHAT.

So: that stressful meeting? The enraging conversation? The moment that sent your heart rate up and your jaw tight? Move your body as soon as you can. Go for a walk, do fifteen air squats, or do 50 jumping jacks. Your largest muscle groups are in your legs, which means squats and leg movements are pulling glucose out of circulation fast and efficiently — blunting the insulin spike before it happens, and giving those stress hormones somewhere to go the way your body always intended them to.

3. Act Accordingly.

Now that you know what cortisol does to your body — how it raises insulin levels which keep you in fat storage mode — act differently when you're in a stressful state. Instead of stress eating, stress drinking or stress scrolling, act to diffuse your stress levels. Acknowledge that you're more stress sensitive in this period of your life, and engage in some stress reducing activities (just 20 minutes a day can work wonders):

Meditation. Stop rolling your eyes, because the research on this is not soft — even ten minutes of daily meditation measurably reduces cortisol output over time by downregulating HPA axis activity. Yes, you're calming your mind, but more importantly: you're literally retraining the system that controls how much cortisol you produce. If you've tried it and it didn't stick, I urge you to keep at it. Sit in the stillness and overcome your racing thoughts; the moment you catch yourself thinking is the moment you start rewiring your mind and your nervous system. Once upon a time, not too long ago, I remember throwing my phone across the room because I couldn't meditate for 10 minutes on the insight timer app. Today I'm a daily meditator, and meditate for a minimum of 30 minutes each day. It's a non-negotiable for me to keep my nervous system in balance.

Journaling. This is a wonderful way to get all the racing thoughts out and on paper and it directly lowers cortisol. Research out of UT Austin by psychologist James Pennebaker shows that expressive writing about stressful or emotional experiences measurably reduces cortisol, improves immune function, and lowers anxiety over time. The working theory is that when you externalize a stressor onto paper, your brain stops having to hold it in active memory — and that cognitive offloading directly reduces HPA axis activation. Ten minutes, no rules, just freeform your thoughts onto paper of whatever is sitting in your nervous system.

Breathwork. Another underrated tool that seriously works. Slow, diaphragmatic breathing — specifically extending your exhale longer than your inhale — directly activates the parasympathetic nervous system, which is the physiological opposite of the stress response. Box breathing, 4-7-8, coherence breathing — these are all direct interventions on your autonomic nervous system. And they work fast. We're talking minutes, not weeks. This is one of the few tools you have that produces an immediate, measurable shift in your cortisol response — and you can do it anywhere. PS the physiological sigh inhale / exhale is how I fall asleep every night. I try for 10 breaths and never make it past 8. 

Vagus nerve stimulation. Your vagus nerve is the primary pathway of your parasympathetic nervous system — the long nerve that runs from your brainstem down through your heart, lungs, and gut, and essentially carries the signal that tells your body it's safe to stand down. When vagal tone is high, your stress response is regulated and resilient. When it's low — which chronic stress and poor sleep will do — your nervous system stays stuck in threat mode. The good news is vagal tone is trainable. Cold water on your face or a brief cold shower, humming, singing, gargling, slow rhythmic breathing — all of these stimulate the vagus nerve and shift your nervous system state. It sounds almost too simple. The physiology is real.

Grounding. Direct physical contact with the earth — bare feet on grass, sand, soil — has a measurable effect on cortisol and inflammatory markers. The research here is compelling: electrons from the earth's surface appear to have an antioxidant effect that reduces inflammation and supports nervous system regulation. One of my favorite things to do on beach vacations is to go for a long walk on the beach, and shocker: I sleep incredibly well those nights. I think of it as the easiest free intervention available to me, and if you're able to get outside and ground, I highly recommend it. 

Nature and non-sleep deep rest. Time in natural environments consistently and measurably lowers cortisol — this is well established in the research. Even twenty minutes outside in a green space produces a significant drop. And non-sleep deep rest practices — yoga nidra, guided body scans, even a genuine do-nothing rest period in the afternoon — allow your adrenal system to recover in a way that staying busy simply doesn't permit. Rest is not laziness. In a chronically cortisol-elevated body, it is medicine.

Movement as regulation, not punishment. A slow walk, especially outside, is one of the most effective cortisol-lowering tools you have. It moves your body enough to burn off stress hormones without adding physiological load. If you're in a high-stress season and your nervous system is already taxed, a thirty-minute walk in fresh air will do more for your hormonal health than a forty-five minute HIIT class. And remember to be in movement balance. If you've got a strength training session, balance that out at the end with 5-10 minutes of gentle stretching, to tell your nervous system you're safe and out of fight or flight. 

The thread connecting all of these is the same: you need to honor and work with your nervous system rather than pushing through it. That might've worked before, but in midlife, with a more reactive HPA axis and a thinner hormonal buffer, either you learn to honor and work with your nervous system or it will work against you.  

Let's talk about sleep. 

Sleep deprivation is one of the most powerful cortisol triggers we know of. A single night of poor sleep measurably elevates cortisol the next day, increases appetite, and reduces insulin sensitivity. Studies consistently show that sleep-deprived people consume significantly more calories, crave high-sugar high-fat foods specifically, and store a disproportionate amount of gained weight as fat rather than lean mass.

In perimenopause, when night sweats and hormonal fluctuations are already wrecking your sleep architecture, this compounds fast. Poor sleep drives up cortisol. Elevated cortisol impairs sleep. Both drive insulin dysregulation. And insulin dysregulation makes the entire hormonal picture worse. You cannot eat your way around a chronically sleep-deprived, cortisol-dominant nervous system. I wish I could tell you otherwise.

What can you actually do about it?

The answer here is not primarily dietary — and I know that's hard to hear when we've been conditioned to believe that weight is purely a food and exercise equation. When cortisol is the primary driver, the most powerful levers are nervous system regulation, sleep, and managing the physiological stressors that most of us don't even recognize as stressors.

Protect your sleep like it's a non-negotiable. Seven to nine hours is the physiological minimum for cortisol regulation and insulin sensitivity — not a luxury, not something to optimize around your schedule. Anchor your sleep and wake times. Create a wind-down that actually works for you. And if night sweats are disrupting your sleep, address them with your physician. This is not small stuff.

Reconsider how much high-intensity exercise you're doing. Exercise - including strength training - is a physiological stressor. In the right doses, it's one of the best things you can do for your health. But if your cortisol is already chronically elevated, daily intense training can add adrenal load to a system that's already overtaxed. Strength training two to three times a week paired with walking tends to produce better hormonal outcomes in this phase than chronic cardio. Less is genuinely more in this instance, so remember to schedule rest days and adhere to that.

Do not undereat. Significant caloric restriction is also a cortisol trigger. Your body interprets a hard deficit as a survival threat and responds with elevated cortisol and a compensatory slowdown in metabolism. This is the trap so many women in midlife fall into: eating less drives up cortisol, which drives up insulin, which drives fat storage. Adequate protein — at minimum 1.2 to 1.6 grams per kilogram of bodyweight — and reasonable overall calories is metabolically far more productive than restriction.

Protect your nervous system on purpose. The things I just mentioned, like meditation, breathwork, walking outside, genuine rest, and reducing digital noise in your evenings — these have measurable, evidence-supported effects on cortisol output. Even brief daily diaphragmatic breathing practices show clinically meaningful cortisol reductions over time. 

Here's the Takeaway

We can quiet the gym-bros for once and for all: weight loss resistance in midlife is almost never just a calories-in-calories-out story. It's a complex and nuanced hormonal conversation with insulin and cortisol at center stage, and it's something most people simply don't know about. When cortisol is chronically elevated, it creates an insulin response that works against fat metabolism at the cellular level — regardless of how clean you're eating.

Understanding this changes your strategy, doesn't it? And that's exactly what I built my masterclass around — giving you the full picture of what's happening in your body in midlife, and the tools to work with it, so you can actually achieve your goals and you're not trying and getting frustrated. Again. 

The Aging Well Naturally Masterclass launches this summer! And this is exactly the kind of depth we go into across every module. Keep an eye on your inbox for announcements about when my Masterclass goes on sale. I can't wait for you to experience what thriving in midlife feels like.

Did you like this series? Drop me a note & let me know, I read every comment. 

Let's live into it, wildly.

x

Juliana