Fasting to help balance cortisol and support sustainable weight loss

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At Amchara, we believe you can Change For Good – we are here to support you with education, nourishment, and strategies personalised to your unique health circumstances and goals. Part of this journey often involves gently resetting your body through practices like fasting.

But how does fasting affect cortisol? Cortisol is often known as the "stress hormone", because it's released by the adrenal glands in response to stress. While it plays a vital role in keeping your body functioning – regulating blood pressure, metabolism, energy levels, immune response, and your sleep-wake cycle – it can negatively impact your body when it's out of balance.

Here's what the science tells us, and how our functional medicine based approach can help you balance cortisol at Amchara.

Cortisol plays a vital role in balancing blood sugar, metabolism, inflammation, and immune function, especially in response to stress. Naturally it follows a circadian rhythm – peaking in the morning and declining through the day.

However, when cortisol is chronically elevated – due to many factors such as stress, poor sleep, or erratic eating patterns – it can disrupt metabolism and encourage fat storage, particularly around the abdomen. This hormonal imbalance often makes weight loss harder and may create a vicious cycle of stress and weight gain.

Fasting – even as briefly as 48 hours – has been shown to raise cortisol levels. For example, young women undergoing a 48-hour total fast experienced a downward shift in their daily cortisol rhythm, suggesting increased stress response even as they lost weight.

A 2022 clinical study confirmed that a 10 day fast significantly increased both free and total cortisol levels, especially in men. Cortisol rose from 16 to 28 nmol/L (free), and the cortisol-to-cortisone ratio climbed – indicating increased hormone activity.

Similarly, a systematic review comparing fasting with mild calorie restriction found that fasting causes a notable spike in cortisol, but eating fewer calories without fully fasting may not.

When you fast completely, your body senses a temporary shortage of energy. In response, it releases more cortisol – a hormone that helps you tap into stored energy by breaking down fat and muscle and converting them into glucose (blood sugar) to keep you going. This is part of a built-in "survival mode" response.

In contrast, if you simply eat a smaller amount of food (such as on a very low-calorie diet), your body still gets a regular supply of fuel, so the cortisol spike tends to be smaller or may not happen at all. The difference is that fasting puts your body into a stronger "energy mobilisation" mode than gradual calorie reduction does.

Emerging research shows that the timing of fasting – such as in time‑restricted eating (TRE) – can shape cortisol patterns more gently:

• Skipping dinner tends to lower evening cortisol, likely reducing the anticipatory spike before meals.
• Skipping breakfast, however, may increase midday cortisol and flatten the natural cortisol rhythm – suggesting a less healthy stress adaptation.
• Meta-analysis of TRE practices reported that structured fasting windows often result in lower cortisol compared to unrestricted eating, especially when meal timing is regular.

We recognise fasting can pose hormonal stress if it's unmanaged. At Amchara, our functional medicine approach ensures fasting:

• Honours your unique biology
• Respects your stress resilience
• Aligns gently with your circadian rhythm

Here's how we do it:

• Short-term spikes are expected, not dangerous, but need monitoring to prevent over-activation of the stress response.
• Structured fasting schedules, particularly early or consistent TRE, may stabilise cortisol rhythm rather than disrupt it, helping with stress resilience and weight outcomes.
• Moderate weight loss helps reset post-meal cortisol responses to healthier levels in individuals with obesity.
• Functional nutrition approaches, like Mediterranean-style diets rich in polyphenols, can modulate stress responses and support cortisol balance.

Here are five principles you can use – based on science and Amchara's personalised health ethos:

1. Ease in gradually – start with shorter fasts (12–14 hours), or a gentle juice or metabolic reset before considering longer fasts.
2. Align with the clock – favour earlier feeding windows to support natural cortisol peaks and avoid disrupting your rhythm.
3. Stay hydrated and nourished – supplement electrolytes, drink herbal teas, and include nourishing juices to buffer stress.
4. Supportive movement and rest – choose restorative yoga or mindful walks over intense workouts to ease cortisol.
5. Monitor and adjust – listen to your body. If you notice sleep disturbances, mood shifts, or energy dips, pause the fast and reassess.

Fasting can be a powerful tool to reboot metabolism, reset appetite, and help you move toward sustainable weight loss. But cortisol is your body's wise sentinel – its response signals where extra care is needed.

At Amchara, we offer functional, compassionate fasting protocols, grounded in science and personalised to you. If your cortisol is juggling stress, weight, or hormonal imbalance, know that the right support can help it realign, naturally and gently.

We invite you to explore fasting as a journey, not a fad – one that honours your body's rhythm and supports long-lasting change. Your wellbeing is unique, and deserves a plan that's as tender as it is effective.

If you would like to find out more about optimising your health through detoxification, our Amchara retreat is designed to help you detoxify both physically and mentally.

On an Amchara health retreat at Gozo, Malta, you will be immersed in a supportive and nurturing environment, combining a Functional Medicine and naturopathy approach, that enables you to switch off, relax and kickstart your health journey.

Our Personalised Health practitioners will support you, recommending positive, sustainable lifestyle choices tailored to your individual health circumstances and goals, and empower you to 'Change for Good'.