After having delved into insulin, its role in the human body and the concept of insulin resistance, it’s time to shed light on cortisol, the so-called stress hormone.

We’ve gone into a lot of detail into the cortisol and the stress response and explored how stress can affect different individuals in varied ways. In this article, we delve into how this hormone influences our metabolism and can affect weight loss. 

What is cortisol and what is its role in our physiology?

Cortisol, our so-called stress hormone, is released during times of stress and is in charge of our ‘fight or flight response’ in conjunction with our sympathetic nervous system. Back in Palaeolithic times, or the Old Stone Age, this usually referred to physical danger – think running from a predator as if your life depended on it (which it most likely did).

As per Dr. Fung(1), cortisol increases alertness, decreases the need for sleep and enhances the availability of glucose. This allows muscles to derive enough energy needed for the physical activity that would help evade the predator. All resources are essentially focused on the survival of the stressful period, which usually culminates in either fight or flight, in which this glucose is utilised. 

The cortisol levels would then return to normal, until the next time you were in a similar situation. Makes sense so far, right? So what does cortisol, a hormone that primes your body for action, have to do with insulin, our fat storage hormone? 

How does cortisol affect insulin?

The human body is truly a marvel; while insulin and cortisol seem unlikely bedfellows at first glance, they actually have similar effects when it comes to weight gain. Under conditions of stress which last for a short period of time, the roles of these two hormones are completely different.

Unlike insulin, which stores energy as glycogen or fat, cortisol helps to make energy available in forms such as glucose. When the stress persists over a long period of time, however – it’s a different story altogether.

Since we’ve long moved on from hunting and gathering times, modern-day stressors would include things like arguments with loved ones, navigating peak-hour traffic, sleep deprivation and work stress. Right on cue, cortisol levels shoot up – but where is the physical release of this energy, to lower blood glucose? There likely isn’t one. 

Does cortisol cause weight gain?

So chronic stress causes elevated blood glucose levels, but this glucose is not actually utilised – so insulin has to be released to even out the glucose levels. As cortisol levels remain high over a period of time, more and more insulin is required to do the needful. 

As per ‘Investigation of the Relationship Between Chronic Stress and Insulin Resistance in a Chinese Population’(2), chronic stress has been associated with insulin resistance and may contribute to the development of insulin resistance.

Long, continuous exposure to insulin – which inevitably happens due to elevated cortisol levels – results in insulin resistance(3) which can lead to a host of health issues including weight, hypertension, PCOS and type 2 diabetes.

Think of cortisol as a metabolic messenger that’s a double-edged sword; in small amounts when it’s required, it can help you deal successfully with a stressful situation and help in fat burning – and possibly even save your life. With long-term stress, however, insulin and cortisol interact in a way that promotes fat storage and this is what leads to weight gain. 

Is stress relief an active process?

Let’s just accept that stress is inevitable in day-to-day life. After a long day at work, it might be tempting to kick off your shoes and vegetate in front of the television munching on a bag of something delicious, sugary and most definitely loaded with carbs. Curb those cravings and actively try out alternative approaches for stress management.

We suggest you spend some time at least a few times a week doing something that your body will actually thank you for – think yoga, meditation and exercise. Better food habits also go a long way in aiding stress relief. Studies on mindfulness intervention(4) have been able to use methods like these to successfully target and reduce cortisol and abdominal fat. If it’s been a particularly challenging week and you can feel the stress in your muscles, go ahead and pamper yourself with a massage. 

Remember – don’t shoot the metabolic messenger! Work with it, instead.