Stress – it’s that all too common feeling that has somehow become synonymous with modern day life. But aside from the tension and worrying thoughts, how else does stress hijack your body? If you’re someone that reaches for the chocolate in the shadows of a looming deadline to find comfort, you’re not alone. Research shows that our response to stress, can influence our food choices and unfortunately for Dietitian’s, carrots are foregone for chocolates in many of these instances. But what is it about stress that makes us eat what we do, and can we overcome stress by making healthier choices?
How can stress influence our diet?
Stress can be detrimental to our health, by stimulating unhealthier eating behaviours and changes in appetite. Unfortunately for our waistlines, chronic stress has shown to be associated with a greater preference for energy- and nutrient-dense foods, especially those that are high in sugar and fat as well as a decrease in desire to eat ordinary meals. In a nutshell, stress drives us to pick pizza over pumpkin and chocolate over carrots.
This may be explained by an increase in emotional eating and the reward centres within our brain. In stressful situations, we are more likely to give in to our food desires compared to when we are not stressed. For instance, despite a plate of cooked fish, mashed potatoes and vegetables waiting for you in your fridge, you may be more tempted to pick up that phone and order some take-away.
If you’re more inclined to crave your mother’s famous bolognaise there may be some logic to this too. Stress also drives us to eat more “comfort foods”, a term that reflects the idea that palatable food intake reduces the stress response, thereby providing a potential means for people to “self-medicate” for stress relief.
Stress and body weight
It may be no surprise that for some, eating under stressful circumstances can spell bad news for our waistlines. Evidence suggests that chronic stress, which causes higher blood cortisol levels, may be causally linked to weight gain. Cortisol plays an essential role in supplying energy to the body, which is why excess cortisol has been linked to the development of abdominal obesity. Stress-induced increases in cortisol may also increase levels of the leptin hormone. Increases of this hormone in the body may lead to leptin resistance (meaning the body is less sensitive to the actions of leptin) and this is also thought to increase cravings during stress. Therefore, leptin resistance may also stimulate food intake, appetite and consequently, increase weight gain during stress.
But when stressed, if you’ve experienced knots in your stomach and couldn’t stand the sight of food, you’ll know all too well, that stress can also have the reverse effect. More commonly, acute stress rather than chronic stress, is associated with loss of appetite and weight reduction. Research shows that approximately 35–60% of people report eating more total calories when they experience stress, whereas approximately 25–40% of people report eating less.
If stress can lead to unhealthy eating, can healthy eating help us cope with stress?
Currently, most of the studies exploring diet and stress have focused on the effects of stress on dietary behaviours, rather than how diet may influence stress. As such, we do not have enough research to help us understand the direct effects of healthy or unhealthy diets on coping with stress.
At best, studies have shown that in the short-term, intake of palatable and/or high carbohydrate food is associated with improved mood, decreased perceived stress and reduced plasma cortisol concentrations. This is not surprising, otherwise individuals wouldn’t get any benefits from comfort foods as they seem to do. But sadly, chocolate is a quick-fix only. In the long-term, healthier dietary patterns are known to be associated with better mood. In addition, we know that healthy diet may play an important role in our stress-regulation system – the hypothalamic-pituitary-adrenal (HPA) axis – which controls the body’s cortisol levels. For example, adherence to a dietary pattern close to the Mediterranean diet, which was abundant in vegetables, fruits, fish, nuts and olive oil, was shown to be associated with decreased levels of HPA axis disturbances.
What does this all mean?
While we know that stress can influence our eating behaviours, research is not yet at a stage where we can recommend specific dietary advice to help cope with stress. However, we do know that from our own research at the Food and Mood Centre, long-term adherence to healthier dietary patterns is associated with better mood. In short, next time you’re feeling stressed, instead of subsiding to quick-fix cravings try other stress-reduction techniques such as exercise and mindfulness and above all else, pick your carrots over chocolates.
This article was authored by Meghan Hockey and Dr Anu Ruusunen and based on an interview published here for Deakin’s this lifestyle magazine
