We’ve all been there - we’re stressed, in a hurry and hungry, and the easiest snack to grab is a bag of crisps or a sugary doughnut. However, a new study has suggested that snacks that are high in fat could actually make us even more stressed.
Researchers at the University of Birmingham found that high-fat foods eaten before a stressful event occurs can result in reduced vascular function and brain oxygenation, as well as a negative impact on mood.
The study analysed a group of healthy young adults after they ate two butter croissants for breakfast. The participants were later asked to do mental maths tasks that increased in speed and alerted them when they got an answer wrong, which created a stressful environment.
Rosalind Baynham, an author of the study and a PhD researcher at the University of Birmingham, explained: “When we get stressed, different things happen in the body, our heart rate and blood pressure go up, our blood vessels dilate and blood flow to the brain increases.
“We also know that elasticity of our blood vessels - which is a measure of vascular function - declines following mental stress.”
The study found that eating high-fat foods when you’re mentally stressed reduced vascular function by 1.74%, which could increase the risk of cardiovascular disease. Previous studies have shown that just a 1% decrease in vascular function can lead to a 13% increase in heart disease risk.
The effects of reduced vascular function also lasted longer in participants who ate high-fat foods during the stressful period. Reduced arterial elasticity was detected in participants up to 90 minutes after they stopped the mental maths tasks.
Consuming high-fat foods while stressed also caused a reduction in oxygenation in the brain, which could impact mood and mental health, leading to further stress, said Dr Catarina Rendeiro, assistant professor in nutritional sciences at the University of Birmingham.
She added: “The impact of these foods during stressful periods cannot be understated… On the other hand, it could affect cognitive function and people’s ability to perform the very task they are stressing about, such as an interview, an exam or a work meeting. This is something we would like to do more research into in the future.
“We know that when people are stressed, they tend to gravitate towards higher-fat foods, either because it is the more convenient option if time is in short supply, or as a treat to deal with the stress.
“But by doing this, they are making their physical and psychological response to stress worse. By picking low-fat foods, they could be positioning themselves to cope with the stress more effectively.”
Last October, the UK government introduced legislation to restrict the promotion of certain foods and drinks that are high in falt, salt or sugar (HFSS) in a bid to help Britons make healthier choices when it comes to food.
The legislation restricts the placement and price promotion, such as multi-buy promotional offers like ‘Buy One Get One Free’, of HFSS products in shops and supermarkets. In England, the regulation also covers advertising online and on TV before 9pm.
Examples of HFSS food include:
So while it might be tempting to reach for these convenience foods to snack on, we should be aware that they contain a lot of fat, salt and sugar, and may lead to more stress. To reduce stress levels, Baynham advised: “Next time you are in a big meeting, or taking part in a job interview, maybe try and resist the free biscuits and go for some berries instead. You might find you feel more relaxed and can cope with the stress just a little bit better.”
The team at the University of Birmingham suggest consuming healthier snacks to keep stress down, such as:
Other fruits and vegetable
Read more about dealing with stress:
How to reduce stress, according to a counsellor (Yahoo Life UK, 4-min read)
Transcend Work Burnout With This Proven Stress-Beating Strategy (Men's Health UK, 2-min read)
What are micro stresses? The hidden triggers that impact your mental health every day (Yahoo Life UK, 6-min read)