The foods to avoid when you’re feeling stressed (and six simple snacks to reach for instead)

By the time I’ve finished writing this paragraph, a croissant will have been demolished. A 5pm deadline? Rrrrrip goes the lid off the Pringles. There are occasions when I’ve been working on an urgent project, only to discover at the end that a pack of biscuits is now half a packet and I don’t remember a thing about the process.

Most of the time, I eat pretty well. But when I’m under stress, all my healthy eating habits go out of the window. I know I’m not alone in this.

TC Callis is a nutritionist, and the author of The Building Blocks of Life: a Nutrition Foundation for Healthcare Professionals. “Stress is a response to danger, and increases the production of cortisol and adrenaline, the ‘fight-or-flight’ hormones,” she says. “Calories help us survive: eating triggers the cascade of chemicals which release energy.”

The problem is that it’s often the “bad” foods that we crave. A 2021 study published in the journal Neuron showed that eating high-calorie foods while feeling stressed activates the “reward centre” in the brain, leading us to main-line junk food. “Chronic stress fuels the consumption of palatable food and can enhance obesity development,” said the scientists.

They identified a chemical called lateral habenula, responsible for “promoting hedonic feeding under stress” and leading to spikes of the feel-good hormone, dopamine. Dopamine plays an important role in controlling memory, mood, learning and concentration – and our bodies are hard-wired to crave it.

Now comes some research from the University of Birmingham to make us feel even worse about our moral food failings. Eating junk food under pressure can make us feel even more stressed, because of negative reactions in the body, ranging from a rise in heart rate and increased blood pressure, says the new study.

Calories help us survive: eating triggers the cascade of chemicals which release energy.

TC Callis, nutritionist

Subjects were asked to eat two croissants while doing some tricky mental arithmetic, under a time-restricted trial designed to mimic real-life stresses. “Eating the high-fat foods we provided reduced their blood vessel function by 17.4 per cent,” says lead author Rosalind Baynham. “Importantly, we found that this impairment lasted longer when people ate the croissants compared to a standardised lower-fat snack with the same number of calories.” After 90 minutes, the function still had not gone back to normal.

It gets worse: scientists have shown that this repeated cycle of stress-eating can lead to sleep problems, cognitive issues, and heart disease. So how to cope with this snacking catch-22? We asked the experts for the best foods to eat under stress.

How to eat when you’re feeling stressed

Instead of chips, reach for some nuts

“Crisps are top of the list,” says nutritionist TC Callis. “The salt from crisps increases the release of the stress hormones on the HPA (hypothalamic-pituitary-adrenal) Axis, which can lead to raised blood pressure, feeling flushed, and a faster heart rate.

“You might not notice this because you are already stressed, but the salt is almost certainly making it worse,” Callis says. In the longer term, crisps are a no-no because their high salt content increases the risk of developing blood-pressure related circulatory problems such as heart attacks.

Nuts are a far better choice – as long as they are unsalted. “The substances in nuts can help our body better manage stress, improve our gut health, and promote brain health,” says Dr Gabrielle Lyon, a nutritional expert specialising in brain and thyroid health. But hold the peanuts (high in salt: bad), and go for the plainer variety. “Walnuts are excellent as they include omega-3, which supports brain function,” Callis says. “Brazil nuts contain selenium, an antioxidant which is lacking in our soil here. Almonds are high in cortisol-reducing magnesium – and vitamin E, which also protects against stress.”

Swap croissants for berries

It’s no secret that highly processed carbohydrates lead to obesity and related conditions such as type-2 diabetes. However, snaffling them while stressed can cause extra frazzle in the shorter term. “Foods such as muffins and croissants slow down your digestive system,” says Callis. “The carbohydrates sit in your stomach and your gut. The microbiome (your friendly gut bacteria) do not love highly processed carbs. If you mess this up, it can lead to a reduction of neurotransmitters which can affect your mental health and cognitive processes.”

On the other hand, says Callis, berries “are brilliant. They contain huge levels of the antioxidant polyphenols and flavonoids, which protect us against stress hormones such as cortisol. The most powerful flavonoid is anthocyanin, which is what gives berries their dark red colouring.” There’s no need to splash out on expensive and out-of-season produce: frozen berries are half the price and just as effective.

Swap sweets for grapes

“Unlike chocolate, which can be helpful (see below), sweets don’t contain anything other than sugar and a ton of additives,” Callis says. “Hence, you are headed for sugar spike, crash, spike, crash – and a path towards obesity and type-2 diabetes.”

Meanwhile, red grapes have sugar content – which gives immediate pleasure – but don’t cause this glucose rollercoaster in quite the same way. “The fibre they contain means ‘happy days’ for the gut”, says Callis. “Our microbiome loves them.”

Choose tea instead of coffee

According to Susan Bowling, a psychologist at the Cleveland Clinic in the US, caffeine is bad news. “The natural effects of caffeine stimulate a host of sensations, such as your heart beating faster, your body heating up, your breathing rate increasing – all things that mimic anxiety and stress,” she says. “Psychologically, it’s difficult for your mind to recognise that this is not stress because it feels the same.”

Says Callis: “Coffee increases cortisol and stops the production of adenosine, the chemical which calms you down.”

Tea, on the other hand, especially green tea: “has lots of flavonoids, which bust stress hormones,” she says.

Chocolate is fine, but pick dark instead of milk

“Chocolate is a bit of a weird one,” says Callis. “Even though it’s high in fat and sugar [which is bad for the reasons above] it contains the chemicals theophylline and theobromine, which reduce stress and trigger the production of feel-good hormone serotonin.” If you do feel the need to reach for a bar, Callis recommends dark chocolate, which has lower levels of fat and sugar, and more theophylline and theobromine.

Alcohol doesn’t do anyone any favours

While it’s unlikely you can booze in the office, it might be tempting to crack open a can of G and T before that 5pm Zoom meeting. Not a good idea, says Callis. “Alcohol does not do anyone any favours, on any level,” Callis says. “Yes, up to a point it reduces social barriers, but these swiftly tip over to not being useful. The biochemistry is just as important. Detoxing from alcohol uses up B-vitamins, which are needed for brain function and energy production. A depletion in these will make you more stressed, as will disturbed sleep as you deal with dehydration after drinking.”

The Telegraph, London