Optimization-based meal planning for sustainable diets

Designing sustainable diets within planetary boundaries requires considering not only choosing what foods we eat, but also how foods are planned, purchased, and combined into meals. This thesis examines how optimization-based meal planning can contribute to more sustainable diets by reducing food waste and increasing the consumption of locally in-season foods. A meal planning model generates meal plans and shopping lists while accounting for supermarket package sizes, a key driver of household food waste. Results show that healthy meal plans with negligible food waste are possible, although reducing waste by weight does not always lower diet climate impact. The thesis also explores shifting towards more local and seasonal diets, showing meal plans can increase locally in-season foods at lower cost and carbon footprint while meeting nutritional needs year-round. Overall, the research highlights trade-offs between nutrition, environmental impact, and cost. The findings reinforce evidence for shifting towards more plant-based diets and show how planning and shopping strategies shape sustainability outcomes.