Food Game: A Gamified Interventional Study to Promote Healthy Eating, Lifestyle Behaviours, and Sustainability in Italian High School

<b>Background/Objectives</b>: Adolescence represents a critical period for the formation of lifestyle habits that often persist into adulthood, significantly shaping long-term health outcomes and contributing to the development of non-communicable diseases. This study aims to assess the impact of Food Game, a secondary school-based programme, delivered throughout the academic year, to promote healthy eating, physical activity, and sustainability awareness among students. <b>Methods</b>: As part of the Food Game programme, 184 adolescents aged 14-16 years from the Milan area (Italy) completed two questionnaires, administered before and after the intervention (November 2024, April 2025), evaluating dietary habits, lifestyle behaviours, and attitudes toward sustainability. This uncontrolled intervention study assessed dietary changes using a composite score [0-14], with higher scores indicating healthier eating patterns. Pre-post intervention differences were analysed using paired <i>t</i>-tests for continuous variables and McNemar's test for categorical variables. <b>Results</b>: After participation in Food Game, a significant improvement in mean dietary score from 7.6 to 8.2 (<i>p</i> < 0.001) occurred. Overall, 28.3% of the students worsened their score and 53.2% improved (≥1-point increase), including a significant improvement (≥2-point increase) in 29.4%. Fruit, vegetable, and fish intake increased, while consumption of meat, processed meat, and snacks decreased (<i>p</i> < 0.05). Waste recycling did not change (94.6%), and tap water non-significantly increased. No significant changes were observed in water intake, physical activity, screen time, or addictive behaviours. <b>Conclusions</b>: These findings support the potential of peer-led gamified interventions to promote healthier eating in youth. Future controlled studies are required to rigorously evaluate the Food Game programme's effectiveness in relation to adolescents' diet, lifestyle, and sustainability habits.