Is Cortisol Really Making You Fat? The Stress Myth Women Need to Stop Believing
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Cortisol has become one of the biggest buzzwords in women's health. Can't lose belly fat? Cortisol. Waking at 3am? Cortisol. Exhausted but unable to switch off? Cortisol.
But is this hormone really responsible for everything we're blaming it for?
In this episode of the Biohackher Podcast, Azra sits down with exercise scientist Amelia Phillips to unpack what cortisol actually does in the female body — and where the wellness conversation may have gone too far.
Amelia reveals that in a recent group of 65 women who underwent cortisol testing, only four returned what she describes as a healthy cortisol response. While the group was not representative of the general population, the results highlight just how significant stress dysregulation can be among women already experiencing symptoms.
They explore what happens when the body moves from a healthy stress response into being constantly "wired and tired", why some women feel exhausted during the day but wide awake at night, and why waking around 3am may offer clues about what is happening with your stress response.
They also tackle one of the biggest claims circulating on social media: the "cortisol belly". Amelia argues that while stress can contribute to weight gain indirectly through disrupted sleep, appetite, cravings and reduced activity, cortisol is rarely the sole root cause of stubborn weight. Insulin resistance may be another important piece of the puzzle.
The conversation also dives into some of the most debated advice for women right now — from intermittent fasting and fasted training to HIIT, cold plunges and sauna — and why there may not be one perfect protocol that works for every woman.
In this episode:
What cortisol actually does — and why we need it
The difference between healthy, elevated, blunted and dysregulated cortisol patterns
Early signs your stress response may be struggling
Why you can feel exhausted yet unable to switch off
The connection between cortisol, melatonin and waking during the night
Why midlife can become a particularly intense period of stress for women
Is there really such a thing as a "cortisol belly"?
Why insulin resistance may be worth investigating when weight won't shift
How stress interacts with perimenopause and menopause
Whether women should exercise fasted
When intermittent fasting may — and may not — be appropriate
Why Amelia believes many women are doing too little intense exercise rather than too much
How to tell when exercise has crossed into overtraining
Cold plunges versus sauna and contrast therapy
How movement can help the body process an acute stress response
The role of blood sugar and nutrition in managing stress
Which cortisol and hormone tests may provide useful insights
If you've been told to exercise less, stop fasting, avoid HIIT and blame your stubborn belly fat on cortisol, this conversation might make you rethink some of that advice.
Because cortisol isn't the enemy. The bigger question is whether your stress response is working the way it should.
Biohackher – Live Well Longer is your practical guide to adding life to your years. Drawing on the latest science in women's health, longevity and biohacking, this book cuts through the hype to reveal what actually works to support your brain, body, beauty and balance as you age. From sleep, hormones and gut health to strength, stress, nutrition and cutting-edge longevity tools, you'll discover evidence-based strategies to help you feel stronger, sharper and more vibrant at every stage of life. Released 27 October, 2026.
