Have you ever found yourself lunging for the secret lolly stash at work after a stressful meeting? Or chosen hot chips over salad for lunch after a busy morning of running about?
Well, it might be time to empty the secret chocolate drawer at your desk, as a new study, published in Neuron, has found that work stress might be making us fatter.
Researchers from the University of Zurich have found that stress can cause reduced self-control and make us sabotage our healthy eating.
Participants in the study, who were all trying to maintain a healthy diet, were split into two groups, with one group undergoing stress; afterwards, the participants were given a self-control dilemma by choosing their own food reward between healthy and unhealthy food.
It was found that those who had undergone stress were more likely to have less self-control and choose a short-tem taste reward via the unhealthy food option available.
The study’s lead author Silvia Maier says the findings “provide an important step towards understanding the interactions between stress and self-control in the human brain, with the effects of stress operating through multiple neural pathways”.
A functional magnetic resonance imaging (fMRI) scan of participants found that stress was accompanied by increased functional connectivity between the ventromedial prefrontal cortex, which has been shown to play an important role in decision-making and regulation of emotions, and the amygdala and striatal regions that encode for food tastiness.
Stress was also associated with a reduced connectivity between the ventromedial prefrontal cortex and the dorsolateral prefrontal cortex regions, which are linked to self-control.
Senior author Todd Hare from the Laboratory for Social and Neural Systems Research at the university explains that the study indicates that even moderate levels of stress can impair self-control.
“Moderate stressors are more common than extreme events and will thus influence self-control choices more frequently and for a larger portion of the population,” Professor Hare said.
Associate Professor Amanda Salis, from the University of Sydney’s Boden Institute of Obesity, Nutrition, Exercise & Eating Disorders, said these findings “help to explain why some people eat more in response to stress”.
“We know from research that some people and animals respond to stress via an increase in food intake, whereas others respond via a decrease in food intake,” Associate Professor Salis said.
Cortisol, a hormone produced by the adrenal gland that helps regulate the body’s response to stress, has also been found to play an important role in brain connectivity patterns.
“High levels of cortisol … can contribute to weight gain … [and] make your body more efficient at storing kilojoules from food as fat, particularly in the midriff region,” Associate Professor Salis said.
A 2014 study published in the Journal of Consumer Psychology found that our mood could greatly influence our food preferences, with positive mood being linked to healthy food choices and negative mood being linked to “indulgent” food choices.
Dr Vivienne Lewis, a clinical psychologist and professor from the University of Canberra, said stress could also impair other lifestyle behaviours.
“When people are under stress, they’re more likely to choose things that are unhealthy for them, whether it be food, alcohol or drugs, whereas those who are more relaxed are more likely to choose to engage in behaviour that is healthier for them,” Dr Lewis said.
“The clients I see in my private practice who score very high on levels of stress … there is a strong correlation with their engagement in unhealthy behaviour, often unhealthy eating behaviour.”
Dr Lewis says employers can work towards making the work environment less stressful for their employees by striking an optimal work-life balance.
“It gives people time to exercise and time to relax, as flexible working conditions and working hours let people fit in healthy lifestyle activities within work,” she said.
As to the question of whether a stressful work environment is making us fatter, Dr Lewis said it is “certainly contributing to it”.