Are healthy diets also sustainable? Experimental study using a Fake Food Buffet

Interventions to promote healthy and sustainable diets are urgently needed to curb growing obesity rates and greenhouse gas emissions. To date, little is known about consumers' awareness of the co-benefits of healthy and sustainable diets. Studies furthermore lack a global perspective. This study therefore aimed (1) to compare the composition of sustainable, healthy, and typical meals using an experimental Fake Food Buffet (FFB) study and (2) to compare sustainable diet knowledge and perceptions between individuals who grow up in Global North and Global South countries. The experiment used a 3 Meal Type x 2 Region mixed design. Participants ( N = 74), of which half grew up in the Global North and South, respectively, were asked to self-serve three meals (typical, healthy, sustainable) from the FFB and to complete the Food Sustainability Knowledge Questionnaire (FSKQ). Sustainable meals contained more vegetables, grains, legumes, and plant-based protein ( Fs [2, 144] ≥ 4.26, p s ≤ .016), and less red meat, animal-based protein, and sugar than healthy or typical meals ( F s[2, 144] ≥ 11.77 p s ≤ .001). FSKQ scores did not differ between regions ( W [71.82] = 0.58, p = .564). However, participants from the Global North self-served more vegetables, grains, and plant-based protein from the FFB compared to participants from the Global South ( F s[2, 72] ≥ 4.89 p s ≤ .003). Many people are not fully aware of the substantial overlap of healthy and sustainable diets. Furthermore, culture influences food choices and thus needs to be considered when designing and implementing dietary interventions on a global scale. • Within-subjects experimental study comparing the composition of healthy, sustainable and typical meals. • Used realistic food replicas to assess food choices in controlled but realistic setting. • Included participants from both Global North and Global South countries to increase geographical representation.