Food systems should be at the heart of Cambodia’s development, positively influencing health, economic growth, and climate resilience while creating food security. Yet current diets, dominated by large amounts of rice and excessive ultra-processed foods and sugar, are driving a triple burden of malnutrition: undernutrition, micronutrient deficiencies, and overweight and obesity. To support a shift toward healthier, more sustainable diets, a new analysis led by the World Food Program (WFP) and the World Bank utilizes innovative optimization to derive diet baskets that are healthy, meaning they are nutritious and diverse. The analysis also examines how food production systems can contribute to healthier diets and climate goals. It reviews climate-smart production practices (such as improved yields, reduced post-harvest losses, laser land leveling practice, and sustainable rice platform practices) currently implemented through four projects in rice and livestock supported by the Global Agriculture Food Security Program (GAFSP), showing their potential to reduce greenhouse gas (GHG) emissions while improving productivity and resilience. These practices offer practical and scalable models for transitioning away from high-emission, input-intensive farming. Fortified rice is highlighted as a particularly cost-effective solution to address micronutrient deficiencies, especially for low-income households that cannot afford sufficiently diverse diets. Sustainable Healthy Diets in Cambodia explores sufficiently diverse, and hence nutritious, diets, including alternative protein sources, such as legumes, eggs, and insects, which offer a lower environmental impact and nutrient-rich options to reduce reliance on environmentally intensive animal source foods. Complementing these production solutions, the analysis highlights the role of social and behavior change (SBC) strategies in shifting demand toward healthier diets. Drawing on a GAFSP-supported model, it illustrates how a targeted approach to behavior change, coupled with community engagement, can be designed to complement nutrition behavior change initiatives in the health sector in order to increase demand for healthier, more sustainable diets.