Why You Can’t Lose Weight in Perimenopause (It’s Not What You Think)

Can I tell you something that took me an embarrassingly long time to figure out?

I’m a certified health coach. I know about nutrition. I know about hormones. I’ve spent years helping other women shift weight, balance their energy, and feel like themselves again. And then perimenopause walked in and sat down uninvited, and suddenly I couldn’t shift a single pound no matter what I did.

I was eating well. Moving my body. Doing all the things I’d told clients to do for years. I was living abroad at the time (somewhere warm, which you’d think would help, lots of walking, fresh food) and still nothing was happening. The weight sat there. The belly stayed put. I was exhausted in a way that sleep didn’t fix.

Isn’t it mad how you can think you know something, and then your own body comes along and completely humbles you? That’s me 😂

So I went properly digging. And what I found changed everything, not just for me personally, but for every woman I work with now.

The reason you can’t lose weight in perimenopause probably has nothing to do with what you’re eating. It has everything to do with your cortisol.

First, What Actually Happens to Your Body in Perimenopause

Here’s what nobody really explains properly. Perimenopause isn’t just about oestrogen dropping. It’s about your entire hormonal system going through a massive transition, and your nervous system being caught right in the middle of it.

Oestrogen and progesterone start fluctuating wildly. Some days you have too much, some days not enough. Your body doesn’t know what’s coming next. And when your body feels uncertain and unsafe, it goes into protection mode.

That means one thing above everything else: it holds on to fat.

Not because you’re doing anything wrong. Not because you need to try harder or eat less or finally commit to the gym. But because your nervous system has decided, on a biological level, that this is not the time to release stored energy.

Do you know what that actually means? All the calorie counting, all the extra cardio, all the willpower in the world — none of it works when your nervous system is in survival mode. You’re fighting against your own biology. And you will lose that fight every single time. It’s not a discipline problem. It’s a design problem.

So What Is Cortisol and Why Does It Matter?

Cortisol is your stress hormone. It’s not a bad thing. You need it. It gets you out of bed in the morning, helps you respond to pressure, keeps you alert when you need to be alert.

The problem is chronic cortisol. The kind that’s constantly elevated because life is relentless, sleep is broken (more on that in another post), your blood sugar is all over the place, and your body is dealing with a hormonal shift it has never experienced before.

When cortisol is chronically high, a few things happen and none of them are fun:

• Your body stores fat, particularly around your belly. This is a survival mechanism. Your body is keeping fuel close by in case of emergency.
• Your metabolism slows down. Again, survival mode. Burn less, store more.
• Blood sugar becomes harder to regulate. Which leads to cravings, energy crashes, and that 9pm urge to eat everything in the house. We’ve all been there.
• Sleep gets disrupted. Hello 3am wake-ups. Which raises cortisol further. Which disrupts sleep further. It’s a loop.
• Fat burning switches off. Your body prioritises survival over weight loss. Every single time.

To be honest, when I finally understood this properly, I felt equal parts relieved and annoyed. Relieved because it wasn’t my fault. Annoyed because nobody had explained it to me clearly before, and I’d spent months eating less and pushing harder and getting absolutely nowhere.

I wasn’t failing. My body was doing exactly what it was designed to do. I just needed to give it a reason to feel safe again.

Why the Usual Advice Makes Things Worse

Most advice out there for perimenopause weight loss is: eat less, move more, cut the carbs, try intermittent fasting, push through it. And I get it, that advice works for some people at some stages of life.

But in perimenopause? For a lot of women, it actively makes things worse.

• Cutting calories when cortisol is already elevated tells your body there’s a food shortage. It doubles down on fat storage.
• Intense cardio spikes cortisol further. More stress on a system that’s already overwhelmed.
• Skipping breakfast sends your blood sugar crashing before 9am, which triggers a cortisol response that lasts all day.
• Intermittent fasting, especially when hormones are fluctuating, can push your body further into stress mode rather than fat-burning mode.

None of this means you can’t lose weight in perimenopause. You absolutely can. But you have to work with your biology, not against it.

What Actually Worked: The 3 Things I Changed

When I stopped trying to force weight loss and started focusing on making my body feel safe, things began to shift. Slowly at first. Then noticeably.

And I want to be clear that I was going through a lot at this point. My sarcoidosis (a chronic inflammatory condition I live with) was flaring, my hormones were all over the place, and I was doing all of this while managing a move abroad with my family. If it worked in those conditions, it can work in yours.

1. I regulated my nervous system first

Before food. Before exercise. Before anything else. Because none of it works if your cortisol is sky high.

This looked like building a morning that eased me into the day without spiking cortisol straight away (not the aggressive 5am cold plunge variety, just something gentle and intentional), protecting my sleep properly, and doing something every evening that told my body the day was over and it was safe to rest.

Within a week, my body started responding differently to everything else I was doing. It sounds almost too simple. That’s because we’ve been trained to think harder is better. It isn’t always.

2. I fixed my blood sugar

Blood sugar and cortisol are deeply connected. Every time your blood sugar crashes, cortisol spikes to compensate. So I stopped eating the ‘healthy’ breakfasts that were tanking my blood sugar before 9am (yes, the oatmeal and fruit situation) and started building every meal around protein, fat, and fibre.

The afternoon cravings I’d had for years, the ones I genuinely thought were just part of my personality? Gone within about five days. I was not prepared for that.

3. I changed how I moved

I stopped doing the long, intense workouts that were leaving me exhausted and, as I now understand, making my cortisol worse. I switched to shorter, more intentional movement. Walks. Specifically, a 10-minute walk after every meal.

I know how that sounds. It sounds like not enough. But the impact on my blood sugar, my belly bloat, and my energy was genuinely surprising. I started tracking it properly because I couldn’t quite believe it myself.

The honest truth? I didn’t lose weight by trying harder. I lost weight by doing less, but doing the right things, in the right order, for where my body actually was. That’s the whole method in a sentence.

Where to Start If This Resonates

If you’ve been reading this nodding along and thinking ‘that’s me’ — I really do see you. Because I was you. Doing everything right on paper and getting nowhere, convinced there was something specifically wrong with me.

There isn’t. And there isn’t something wrong with you either.

Your body is responding completely logically to the situation it’s in. It just needs a different signal. And the place I always tell women to start is cortisol, not food, not exercise, cortisol first.

When you start to regulate your stress response, your body finally feels safe enough to let go of the weight it’s been holding onto. Everything else (the food, the movement, the sleep) starts to work the way it’s supposed to.

The Bottom Line

Perimenopause weight loss isn’t about trying harder. It’s about understanding what’s actually happening in your body and giving it what it needs.

Your cortisol is running the show right now. And the good news is, once you know that, you can actually do something about it.

You are not broken. You are not failing. You just need a different approach. And this is exactly where we start. xx