Recent studies suggest that hunger increases the likelihood of individuals prioritising the taste of food over its nutritional value, which could lead to unhealthy dietary choices. This was the focus of a significant study featured in a revised Reviewed Preprint in eLife, employing sophisticated methodologies such as choice behaviour assessments, eye-tracking, and advanced computational modelling. The evidence supported the hypothesis that when hungry, people are more likely to choose tastiness over healthiness in their food selections.
The ongoing global obesity crisis underscores the importance of addressing dietary choices. According to statistics from the World Health Organization, the number of overweight adults has more than doubled since 1990, and adolescent obesity has quadrupled. By 2022, approximately 2.5 billion adults will be overweight, with 890 million suffering from obesity, which significantly increases the risk of severe health issues, including type 2 diabetes, cardiovascular diseases, and certain cancers.
The immediate environment significantly influences daily food-related decisions. Previous research has shown that displaying nutritional information can promote healthier eating choices. However, evidence also suggests that hunger can skew decision-making towards less healthy options. This preference for energy-dense foods may be an evolutionary adaptation to ensure survival under conditions of food scarcity. With high-calorie food now more accessible and affordable, this adaptive trait may be contributing to rising global obesity rates.
To understand the cognitive processes influencing this behaviour, Jennifer March, a PhD student at the University of Hamburg and lead author of the study, and her colleague Sebastian Gluth, a professor at the same university, conducted an experiment involving 70 adults. After an overnight fast, participants underwent food choice tests in both hungry and satiated states. In the satiated state, participants consumed a protein shake that matched their daily calorie needs at the beginning of the study. They evaluated various food items, ranking them based on taste and perceived caloric content.
The experiment’s findings revealed a consistent preference for taste over health, irrespective of the hunger state, but significantly intensified when participants were hungry. This preference aligns with previous studies suggesting that hunger enhances the perceived reward of calorie-dense foods. The study’s innovation lies in demonstrating that visual attention patterns and cognitive weighting influence this bias in decision-making processes. When hungry, participants focused more on the visual appeal of food and disregarded nutritional ratings unless they concentrated explicitly on them.
While this study was conducted in a controlled lab setting, future research could explore how these findings apply in real-world environments like grocery stores or restaurants, where external cues and marketing strategies might further influence consumer choices. Professor Gluth summarises the study’s implications, noting that hunger makes unhealthy and tasty food more appealing and alters the brain’s decision-making process by shifting the priority given to different types of information. Public health interventions should aim to redirect attention towards nutritional information to counteract the innate tendency to opt for calorie-rich foods when hungry, thus promoting healthier eating habits.
More information: Jennifer March et al, The Hungry Lens: Hunger Shifts Attention and Attribute Weighting in Dietary Choice, eLife. DOI: 10.7554/eLife.103736.2
