Weight gain? IBS? Nutritionist reveals why your cortisol levels may be to blame

Weight gain? IBS? Nutritionist reveals why your cortisol levels may be to blame

Weight gain, IBS and migraines could be caused by elevated cortisol levels. Nutritionist Kim Pearson explains why and what we can do to reduce stress

By now, most people have heard of cortisol and are perhaps aware that it’s connected to stress.

For those who still aren’t sure, cortisol is the body’s main stress hormones and is released by the adrenal glands (which sit on top of the kidneys).

Cortisol helps our body to adapt to a variety of stressful situations. It’s involved in a wide range of different processes throughout the body such as, regulating our metabolism, suppressing inflammation and helping to regulate our sleep-wake cycle.

some types of stress are prolonged and have a negative impact on the body

Any stressors can influence your body’s release of cortisol – these can be emotional, mental or physical.

Some stress, like exercise, is good for you. It’s temporary, unlike prolonged stress which is particularly detrimental to the body. The body adapts to the stress it causes and comes back stronger. But some types of stress are prolonged and have a negative impact on the body, such as:

  • Psychological stress – eg. work, family, partner.
  • Lack of sleep.
  • Alcohol, caffeine and poor blood sugar balance.
  • Shift work, disturbed sleep/wake cycle.

READ MORE: Could stress be causing your bloated stomach? 7 things this expert says you should do

cortisol and stress woman overworked

So, is cortisol good or bad?

You may have heard of the ‘fight or flight’ response that occurs when you’re faced with a stressful event. During this response, cortisol is released from the body’s adrenal glands and floods the body with glucose (the simplest form of carbohydrate and preferred energy source) to give muscles an immediate supply of energy.

This is the body’s way of preparing itself to either fight or flee from the stressor. In evolutionary terms, stress would commonly pose a threat to our survival meaning we’d have to take physical action to save ourselves. Hence the readily available energy would be helpful.

However, in today’s society, where it’s more likely to be a bad driver or our boss causing our stress, physical fighting or fleeing aren’t such appropriate responses.

So this elevated level of sugar in our bloodstream isn’t used up by the physical activity it was being summoned for and is typically left circling in our blood stream.

Consistently elevated cortisol can keep your blood sugar elevated and put you at greater risk of weight gain and type 2 diabetes.

consistently high levels of cortisol can compromise our health

Insulin (the hormone that carries sugar into cells and reduces blood sugar) is also released. If you want to prevent the glucose from being stored as fat, you need to take steps to use up the glucose released. Getting out for a walk and focussing on deep breathing is a good way to achieve this, reducing stress both physically and psychologically.

Once the short-term stress is addressed, hormone balance returns to normal.

While a little stress may be good for you, consistently high levels of cortisol can compromise our health in a number of different ways and how stress impacts us varies from one person to the next.

It’s well established that chronic high levels of stress increase our risk of high blood pressure and can lead to heart disease.

Studies have also shown links between high levels of stress and cancer. Stress suppresses the immune system leaving us less able to defend ourselves against bacteria and viruses.

When your body is on high alert cortisol can stimulate the ‘shutting down’ of certain functions of the body including digestive, reproductive systems and even growth.

It can also trigger symptoms of IBS as well as headaches and migraines. You may also feel anxious, tired, depressed, overwhelmed and struggle to sleep.

READ MORE: 8 easy ways to really soothe stress

cortisol stress levels frayed rope

Stress & weight gain

Cortisol isn’t all bad though as it keeps inflammation levels down, regulates your blood pressure, controls your sleep/wake cycle and can boost your energy, so you can better handle short-term stress.

But when you have too much cortisol, from too much stress, it can also lead to weight gain – especially around the middle.

As mentioned, stress can affect different people in different ways. From a behavioural perspective, some people find that they don’t want to eat when they feel stressed, while for others it can trigger the desire to comfort or binge eat.

Stress and elevated cortisol levels can negatively affect our weight by impacting the normal functioning of our metabolism.

Cortisol can drive up levels of sugar in our bloodstream and compromise our tissue’s response to insulin, the hormone that transports sugar out of the blood and into cells.

Prolonged elevation of cortisol can also lead to muscle breakdown. As muscle is very metabolically active, the more we have of it, the more energy we burn even at rest.

healthy weight loss is about so much more than ‘calories in vs calories out

A reduction in muscle reduces our metabolic rate thus increasing our tendency to gain weight.

Cortisol is also strongly linked to abdominal weight gain, meaning that if we have higher levels of cortisol, we are more likely to gain weight around the middle.

I have worked with clients who, prior to seeing me, were significantly restricting their calories and carrying out high intensity exercise several times a week, yet their weight was not coming down.

This is one example of why healthy weight loss is about so much more than ‘calories in vs calories out.’ These women were definitely in a calorie deficit!

However, the lack of food and intense exercise was causing such stress to their bodies, it stopped them from losing weight. In cases like this I will encourage my clients to consume a higher calorie, nutrient dense diet and reduce their exercise. Perhaps swapping the HIIT for gentle yoga or daily walks.

Surprisingly, in cases like this, eating more and exercising less can be what ends up helping them to lose weight. We are all different and there is no one size fits all approach to weight loss and health optimisation.

As a nutritionist, it’s my job to identify the best strategy for each client’s unique challenges, health status, goals and lifestyle.

READ MORE: How to relieve stress – 3 things this TV doctor wants you to know 

high cortisol levels can lead to weight gain woman looking at body in mirror

How can we measure our cortisol levels?

At my clinic we run adrenal stress tests to assess our client’s cortisol levels over the course of a typical day. We use the Comprehensive Adrenal Stress Test from Genova Diagnostics.

This test is carried out at home where saliva samples are taken at four or five key times over the course of the day.  It gives us a very clear indication of how our client’s body is responding to stress – see image below.

Levels should gradually decline throughout the day

We want to see a healthy pattern with cortisol levels highest in the morning when the body needs to activate and get ready for the day.

Levels should gradually decline throughout the day and be lowest in the evening, prior to winding down for bed.

When this pattern is out of line, or when levels are consistently too high or too low throughout the day, we need to take measures to address and normalise levels.

READ MORE: Stress eating comfort foods? Break your unhealthy food habits with these simple tips

chronic stress and cortisol chart adrenal protocol

The advice we give clients around optimising their cortisol levels depends on the individual’s unique situation and results. However, there are some general steps we can all take to minimise stress…

How can we minimise stress and reduce our cortisol levels?

Work on setting good foundation that manages your stress and cortisol levels. Getting enough good quality sleep and adopting regular de-stressing techniques such as a massage, meditation or Yoga is a great place to start.

When we work with clients we talk through the main drivers for their stress and identify which stressors can be avoided and which have to be managed, and how. Sadly we can’t all give up our stressful lives and go to live on a tropical island.


To start with, look to eating a healthy diet and stabilising your blood sugar levels, which will help to regulate cortisol levels.

What we eat can either support our bodies in times of stress, or it can make our body significantly more stressed.

sugars and refined carbohydrates can cause fluctuating blood sugar levels

A balanced diet focussed on whole foods, optimal amounts of protein, healthy fats and vegetables will support stable blood sugar levels and provide our body with the nutrients it may require in periods of elevated stress.

However, highly processed foods, sugars and refined carbohydrates can cause fluctuating blood sugar levels which can trigger the release of stress hormones and increase stress on the body.

Caffeine and alcohol also drive up levels of cortisol, so try to cut down on these where possible.

READ MORE: Brain food: 7 key nutrients for a healthier brain

minimise high cortisol levels with a healthy balanced diet


I can’t overstate the importance of sleep.

Suboptimal amounts and quality of sleep can drive up cortisol levels. Ensuring you prioritise sleep and getting at least eight hours a night will help to regulate cortisol output.

Supplements like ashwagandha (eg. Link Nutrition’s), rhodiola and magnesium (eg BetterYou) have been shown to help lower cortisol levels.

Mindfulness and relaxation practices such as yoga, deep breathing, meditation and journaling are supportive habits to get into.

Suboptimal amounts and quality of sleep can drive up cortisol levels

Aim to go to bed at the same time each night and allow for at least eight hours in bed. Switching off screens at least an hour before bed can help you get better sleep so try reading a book or meditating instead.

If you have no choice but to be in front of a screen before bed, wear blue light blocking glasses. Sleeping in a completely pitch black room will indicate to your body it’s time to sleep and if you struggle to get off to sleep, try listening to a sleep meditation.

READ MORE: Why can’t I sleep? 8 reasons your gut health could be to blame

reduce cortisol levels with adequate sleep


Spending time doing hobbies you enjoy and being with friends you can talk openly with can help you to process feelings of stress.

The old saying ‘a problem shared is a problem halved’ if often true. Volunteering can also be a wonderful way to feel like you’re giving back and making a difference in the world which can give you an amazing boost.

If you feel overwhelmed, don’t hesitate to get help. There are many fantastic therapists and councillors who can support you in working through your challenges.

For some people a walk is really relaxing, other people really don’t like it

Meditation has plenty of good evidence to show that it’s hugely beneficial for helping to reduce stress, as is yoga and walks in nature – forest bathing is a thing.

Really it’s about finding what works for you. For some people a walk is really relaxing, other people really don’t like it at all – or they might live in an area where it’s not enjoyable to walk.

I always encourage people to consider what relaxes them and do more of that.

If you would like to carry out the Comprehensive Adrenal Stress Test yourself, or if you’d like to find out more about the nutrition, health and weight loss services Kim and her team offer, visit Kim’s website: www.kim-pearson.com

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