A dietitian explains the link between stress and weight gain or loss, including the impact on our hormones and appetite, plus top tips to manage stress levels.
Everyone responds to stressful situations in different ways – some people may lose their appetite completely, while others may crave particular foods or just feel much hungrier than usual. These seemingly simple physical reactions are caused by a complex set of processes and interactions within the body. We asked dietitian Emer Delaney to explain how stress impacts our hormones, appetite, blood sugar levels and fat accumulation, as well as giving her top tips to help us stay healthy during times of stress.
If you're feeling overwhelmed, depressed or struggling to cope, help is available – visit the NHS website or speak to your GP.
How does stress affect our hormones?
Experiencing stress may impact our hormones in a variety of ways. During periods of stress, the body triggers the hypothalamus (a small area at the base of the brain) to sends signals to the adrenal glands, which sit on the top of the kidneys and the pituitary glands (located in the brain behind the nose). This process releases specific stress hormones including adrenaline, corticotropin-releasing hormone (CRH) and cortisol.
Adrenaline is designed to prepare the body for the ‘fight or flight’ response by increasing blood pressure, heart rate and blood glucose levels. It also moves blood from non-essential organs such as the kidneys and skin, to the muscles and brain to help with the ‘fight or flight’ response.
CRH reduces appetite and if this continues long-term, the body releases cortisol.
Cortisol affects a variety of processes in the body including regulating blood sugar levels and metabolism.
How does stress affect appetite?
The impact of stress on appetite can vary from person to person and depends on whether the stressful situation is short-lived or long-term.
Generally speaking, appetite is reduced in the early stages of stress, because adrenaline causes a breakdown of glycogen in the liver and fat from adipose tissue. This provides adequate fuel for the heart and muscles to work as efficiently as possible – which is useful in a 'fight or flight' situation.
Initially, this process results in a decreased appetite as blood is directed away from the digestive system. However, if the stress response is ongoing (such as in cases of long-term daily stress), the production of cortisol increases in the adrenal glands and this is known to stimulate appetite.
How does stress affect blood sugar levels?
Stress can cause higher blood sugar levels as a result of increased production of cortisol.
Cortisol production causes the body to break down protein stores in the liver. This unique process produces glucose (sugar) for the body and over a long period of time, leads to persistent high blood glucose levels. In turn, this can put constant pressure on the pancreas to regulate blood glucose levels by producing insulin – a hormone which lowers blood sugar levels. As a result, over a long period of time, the body may become resistant to insulin – a factor which is linked with type 2 diabetes, gestational diabetes and prediabetes.
Read the NHS website to read more about hyperglycaemia (high blood sugar), and speak to your GP if you are concerned about your blood sugar levels.
How does stress affect fat storage?
There is a specific complex set of interactions that occur in the body between three different organs – the hypothalamus, the pituitary gland and the adrenal glands. This is known as the hypothalamic–pituitary–adrenal axis (HPA). Stress-induced HPA axis activation has been shown to play an important role in body fat accumulation. Its activation increases cortisol production which, in turn, increases appetite and reduces the body’s ability to break down food. As abdominal adipose tissue (fat) has a large number of cells, a high blood flow and more receptors that cortisol attach to, cortisol may have a greater impact on abdominal fat than fat in other areas.
5 top tips to manage stress levels
1. Be as active as you can
You don’t need to be a member of a gym or leisure centre to exercise – brisk walking outside can be a great option to try to introduce into your daily life. It helps to release endorphins, loosen muscles and relax your mind.
Discover more tips to help you get more active.
2. Try meditation
Meditation can be a great way to relax and calm your mind during times of stress. It doesn’t need to be for long periods; just taking a few minutes out of the day to switch off your mind is enough to be very beneficial.
Practising mindfulness may have a similar effect – find out how to eat mindfully.
3. Go decaf
If you are sensitive to caffeine, switching to decaffeinated drinks or herbal teas can help you to feel more calm and less jittery. Ingredients such as camomile and lavender are often said to promote relaxation – try a few different flavours to find one you really enjoy.
4. Pay attention to your diet
Make sure you’re eating regular, nourishing meals and aim for a balanced diet. Some people find cooking helps them to 'switch off' after a busy day, but others may not find it appealing. If this is the case, try batch cooking at the weekends and stock up the freezer with healthy home-cooked meals. Try our favourite healthy batch cooking recipes.
It's easy to get your five-a-day, too. Tinned or frozen fruit and vegetables are as healthy as fresh so making this swap is a great way to eat more without increasing the weekly budget. There is the added bonus that they won’t go off in the fridge if you don’t feel like cooking.
This article was published on 19th March 2019.
Emer Delaney BSc (Hons), RD has an honours degree in Human Nutrition and Dietetics from the University of Ulster. She has worked as a dietitian in some of London's top teaching hospitals and is currently based in Chelsea.
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