Cortisol, Insulin & Oestrogen – The Belly Fat Triangle
- sara6297
- Jun 29
- 3 min read
Updated: Jul 1

The Belly Fat Triangle: How Cortisol, Insulin & Oestrogen Work Against You in Midlife
If you’re eating well, moving your body, and still watching the weight creep up around your middle, it might not be your willpower — it might be your hormones.
For many women in their 40s and 50s, stubborn belly fat isn’t about calories. It’s about a hormonal triangle that keeps the body stuck in fat-storing mode: cortisol, insulin, and oestrogen. When these hormones are out of sync, your body does exactly what it's designed to do: protect you. Unfortunately, that protection often shows up as unwanted fat, especially around your waist.
Let’s explore how each hormone plays a role — and what you can do to start breaking the cycle.
Cortisol: The Survival Hormone
Cortisol is your stress hormone. It spikes when you’re under pressure, not sleeping well, overexercising, or even eating erratically. While short-term spikes are normal, chronic elevation tells your body it needs to conserve energy and prepare for survival — by holding onto fat.
And where does the body store it? Around your belly, where it can be easily accessed for quick energy.
Signs cortisol might be high:
Feeling wired but tired
Waking in the night (especially around 2-4am)
Anxiety or racing thoughts
Craving sugar, salt, or caffeine
Insulin: The Fat-Storing Hormone
Insulin helps move sugar from your blood into your cells. But during perimenopause, your body can become less sensitive to it. That means more insulin is needed to do the same job — and excess insulin = fat storage, especially around the midsection.
What causes insulin spikes?
Skipping meals, then overeating
Too much refined sugar or carbs
Chronic stress and poor sleep
Hidden inflammation in the body
Supporting insulin balance means focusing on blood sugar stability — which comes from regular meals with protein, fibre, and healthy fats, not grazing all day or skipping meals.
Oestrogen: The Shifting Landscape
Oestrogen isn’t just about periods and reproduction. It also affects how your body stores fat, how sensitive you are to insulin, and how efficiently you metabolise energy.
In perimenopause, oestrogen levels become erratic. Sometimes too high (which can worsen insulin resistance), and sometimes too low (which slows metabolism and increases belly fat). That imbalance can make weight gain feel sudden and uncontrollable.
Symptoms of oestrogen imbalance include:
Bloating and water retention
Breast tenderness
Heavy or irregular periods
Mood swings or low mood
How to Break the Belly Fat Cycle
The key to shifting midlife belly fat isn’t punishment — it’s balance. Crash diets and high-intensity workouts often backfire by raising cortisol further and worsening the imbalance.
Instead, focus on gentle, sustainable strategies that bring the body back into regulation:
Prioritise protein at every meal to stabilise blood sugar
Stop eating 3 hours before bed and allow for a 12-hour overnight fast
Use gentle movement like walking, yoga, or strength training
Support stress with adaptogens, magnesium glycinate, breathwork, or journaling
Consider functional testing to see what your hormones are really doing and create a targeted protocol
Real Results Come From Personalised Support
You don’t need to suffer through hormone-driven weight gain or guess what supplements to take. Functional testing can show us exactly where your imbalances lie — so we can support you with a tailored, effective plan.
If you’re ready to explore the root cause of your symptoms and feel more energised, lighter, and clear-headed, I have two resources to help you get started:
Free Hormone Reset Starter Guide
A simple, supportive first step for understanding your hormones and starting to make changes that matter. 👉 Download it here
Reclaim Your Mind: 30-Day Hormonal Reset Protocol (£15)
A deeper, guided journey to reduce anxiety, improve energy, and shift stubborn weight with food, supplements, and mindset tools.
Want to know what your hormones are really trying to tell you? Book a 1:1 consultation or free discovery call below and let’s make a plan that supports your body from the inside out.