According to the well-known NOVA food classification system, ultra-processed foods (UPFs) are industrial formulations derived from chemically modified food components and frequently incorporate additives to enhance palatability, texture, and shelf life. Examples of such products include sugar-sweetened beverages, packaged snacks, instant meals, and reconstituted meats. In contrast to unprocessed or minimally processed foods, UPFs are deficient in essential nutrients, dietary fibre, and bioactive phytochemicals. Instead, they are characterized by high energy density, excessive levels of added sugars, unhealthy fats, and sodium, as well as hyper-palatability, which fosters overconsumption. Recent research has increasingly linked the consumption of UPFs to a wide range of adverse health outcomes, including inflammatory bowel and colorectal cancer. Notably, no existing study has reported beneficial health effects associated with UPF consumption. Despite the well-established health risks associated with UPFs, their consumption remains prevalent across diverse cultural and demographic groups. Systematic reviews with meta-analyses indicate that UPFs make a substantial contribution to national diets around the globe, accounting for up to 80% of total caloric intake in some countries.

Against this backdrop, we propose the development of Wise Gut, a pedagogical card game designed to address the detrimental effects of UPFs and food additives on gut health. Emerging evidence suggests that a diet high in UPFs can disrupt the gut microbiome—the complex community of beneficial microorganisms residing in the human digestive tract—thereby contributing to gastrointestinal disorders. The conceptual framework of the game is informed by cognitive dissonance, a psychological theory which characterizes the mental discomfort experienced by individuals when they hold, simultaneously, two conflicting cognitions, such as ‘eating ultra-processed food’ and ‘knowing the harmful effects of ultra-processed food’. The theory predicts that, when faced with situations that evoke dissonance, individuals will tend to alleviate the discomfort. For example, they may try to modify their behaviour (reducing UPF intake) or rationalize their choices (discounting or trivializing the associated risks).

The Wise Gut game, meant for secondary students, offers players alternative menu options, some of which include UPFs. During gameplay, participants are encouraged to make choices while addressing real-life food dilemmas expressed in terms of cognitive dissonance. After addressing the game's elements and rules, we suggest that, in addition to promoting an interactive and engaging educational experience, the game provides a structured yet non-prescriptive framework that encourages critical reflection on dietary choices, fostering deeper awareness of the implications of food consumption on health. We conclude by raising key questions for further exploration.

Keywords: Ultra-processed food, school lunch menu, card game, cognitive dissonance, gut health.