Abstract
Background: Food waste is a significant global issue with environmental, social, and economic consequences. In 2022, approximately 1.05 billion tons of food were wasted worldwide, with 220 million tons lost during the production and processing stages. Strategies to reduce food waste include full food utilization and the reuse of clean leftovers, which promote food security, efficient resource use, and the valorization of nutrients found in food. Objective: The aim of this study was to map existing scientific literature on nutritional intervention programs that incorporate full food utilization and the reuse of clean leftovers as tools for promoting sustainability and reducing food waste. The review seeks to consolidate existing knowledge, support public policy development, and encourage the adoption of sustainable food practices. Methods: A scoping review was conducted based on the Joanna Briggs Institute (JBI) manual and following the PRISMA-ScR checklist. The search was conducted in four scientific databases (PubMed, Embase, Cochrane Library, and Virtual Health Library) and included articles published between 2014 and 2025. Intervention studies promoting full utilization of plant-based foods and the reuse of clean leftovers were included. Results: After analyzing 2268 studies, 14 relevant studies were selected, with interventions including culinary workshops and educational programs on using parts of food typically discarded, such as peels and seeds. These programs were successful in reducing waste and promoting more sustainable and nutritious diets. Conclusions: Nutritional intervention programs that promote full food utilization and clean leftover reuse are effective in reducing waste and fostering sustainable diets. To maximize their impact, these practices should be integrated into public policies and scaled in institutional settings such as schools, hospitals, and community kitchens.