These things might be true but a change in our nutrition is only looking at one side of the coin.
What is cortisol?
Cortisol is our stress-hormone, produced by the adrenal glands. It follows a daily rhythm being high in the morning to wake us up and lower at night to prepare us for sleep. Alongside regulating sleep, cortisol:
- Controls our stress response triggering the release of glucose for quick energy, enhances brain function, and slows non-essential functions like digestion, during emergencies (think being chased by a tiger). This is your fight or flight response.
- Is linked to how our metabolism functions, such as how your body uses fats, proteins and carbs for energy and storage.
- Increases blood sugar (glucose) to provide energy.
- Influences your blood pressure by making blood vessels more responsive.
- Suppresses inflammation and modulates immune responses.
In short, we need cortisol to function. The trouble is that cortisol can be overactive due to our current daily lifestyles.
In 2025, 91% of adults reported experiencing high pressure or stress at least once in the past year, and 34% said they felt high or extreme stress “always” or “often”.
The increased cost of living, health anxiety in a post-pandemic world, looking after aging parents, bombardment of negative news, burnout and unrealistic societal standards are all reasons for feeling stuck in a constant fight or flight nervous system state, responsible for cortisol production. Being stuck in this state may present high or overactive cortisol levels which has a knock-on effect to our health such as weight gain, sleep problems, anxiety, high blood pressure and high blood sugar, risking Type 2 diabetes.
“This cortisol diet ultimately lowers the impact that cortisol has on your body which in hope will remove belly fat; it doesn’t lower stress itself or address the root cause”
What the “cortisol diet” promises
Online trends claim that unwanted belly fat, fatigue or “cortisol face” are caused by these high cortisol levels. Diets marked as a cortisol detox suggest cutting caffeine, taking supplements such as magnesium and omega-3s. Having balanced meals help stabilise your blood sugar, helping prevent cortisol spikes.
This cortisol diet ultimately lowers the impact that cortisol has on your body which in hope will remove belly fat; it doesn’t lower stress itself or address the root cause.
Lifestyle matters more than diet alone
Adjusting diet alone without looking holistically as your whole lifestyle may help turn the needle on the scale initially, but we also need to look at sleep quality, exercise and stress management techniques. All which are proven to regulate cortisol more effectively than only restrictive diets and supplements. Looking at a whole lifestyle and mindset shift alongside diet is where you’ll see reductions in stress.
These Rockmy resources can keep you further informed:
Gut health and stress Gut health and stress: Understanding the link
Managing your mental load – your health will thank you
Takeaway
If you don’t address the root of your stress or stay stuck in a cycle of overwhelm or burnout, then a change in diet alone isn’t going to fix your cortisol levels. Unfortunately, there isn’t a supplement for that. While eating a balanced diet will help you feel better short-term, if you don’t address the stressor or your coping mechanisms, cortisol will keep building.
Mindfulness, or even therapy, is a good place to start to take the load off and take steps to being stress-free.
Understanding therapy: A guide to the most common approaches in the UK
