Almost everyone today can relate to the terms ”comfort eating“ or ”emotional eating“. In a hectic world, the idea that people treat themselves to their favourite food in order to improve their wellbeing seems to be a compelling contributor to why obesity is on the rise. A lot of us are struggling with the daily hassles of our workplace or private lives from time to time, and if eating “comfort food” provides a quick solution to restore one’s mood, this may contribute to eating more than one actually planned for that day.
Indeed, eating may help to cope with stress – at least in the short run. Eating foods that contain high amounts of sugar or fat may help our body to down-regulate the stress response after experiencing a stressful situation. This appears to be a good thing in the short run, as it allows us to cope more effectively and stop the wear and tear that the stress reaction brings along in the body.
However, if the stress does not cease over a long time, this mechanism may turn against us. When comparing the brain responses of participants who have experienced acute stress before they had their brains scanned with functional magnetic resonance imaging (fMRI) to responses of participants who experienced a non-stressful situation, it becomes visible that the brains of stressed participants react differently to tasty foods: they represent more strongly how much the participant likes the taste of a food, and when given a chance to choose, a stressed person is more likely to go for the tastier snack.
Similar effects have been shown for chronic stress, but to date, we do not know how this comes about. Does stress contribute to forming bad habits about eating, which bias people more towards snack food? Does stress change how our brains make decisions? And can we make these changes visible, or even reverse them? Interestingly, not everyone reacts the same way when stressed: While most people would eat more, German researchers found roughly one third of the population they tested refused eating under stress altogether. What is it that keeps these “stress skippers” away from the buffet, while “stress munchers” go for an extra serving of their favourite snack?
We can ask a similar question when it comes to emotions: When subjects experience unpleasant emotions in a laboratory experiment, they tend to eat more, and less healthy snacks after the study than their peers who experience pleasant emotions. This seems to support the popular notion of “emotional eating”, but if one looks closer into the scientific literature on this topic, we do not have a good toolkit yet that could help us describe what exactly is happening. Did emotional eaters learn to silence their emotions with eating? How do their brains decide differently if they are in different emotional states? And why are some people more affected by this than others? In Nudge-It, we want to develop tools that help us better measure the changes that emotions cause in the way the brain makes decisions. We hope this will eventually help us explain why emotional eating happens and how emotions may affect our food choices.