Image credit: Jennifer March via Canva (CC0)
Many of us will recognise the impact that hunger can have on our food choices, such as making less healthy decisions when grocery shopping. From a scientific point of view, it is an evolutionary advantage to select calorie-rich food when resources are scarce. However, this natural behaviour can lead to unhealthy habits in societies where such foods are easily available.
Dietary choices are based on signals from the body as well as complex cognitive processes. Previous studies have identified that hunger drives increased attention towards foods high in calories. However, it is not clear how this process happens and how it influences decisions.
To address this, March and Gluth studied 70 people who completed a food choice task while either hungry or full. In each trial, participants chose between two foods based on an image (to convey taste) and nutritional scores (to convey health). As expected, hunger shifted choices towards the more appetising and less healthy foods.
Eye-tracking data measured during the experiment revealed that hungry participants spent more time looking at the food images than the nutritional information. March and Gluth then used computational modelling to confirm these findings, showing that hunger increases how strongly people value taste over health and decreases how much they consider nutritional information.
The findings provide new insights into the significant role of attention and valuation in food choices. This could help to advance research on improving dietary habits, which is increasingly important given rising global rates of obesity. The methods used by March and Gluth may also contribute to wider research into how attention to different factors shapes decisions.
