No one would dispute that agricultural systems and food diets are not sustainable from an environmental and health point of view, and that increasing their sustainability must be a major objective of farm and food policies. Simultaneously, climatic, environmental, and health shocks are likely to increase in the coming years. This note defends the idea of an additional double benefit of public policies, aiming at favoring environmentally friendly food systems and healthy diets through two channels: by reducing the risks of developing shocks and by limiting their negative impacts on populations when they occur. As a result, public policies should address, simultaneously and consistently, supply and demand issues. This is illustrated in the case of the European Union. Supply measures should favor the agro-ecological transition of agricultural systems through a more rigorous application of the polluter pays principle, implying notably the taxation of the main determinants of agricultural greenhouse gas emissions (cattle heads and nitrogen fertilizers) and biodiversity loss (mineral fertilizers, synthetic pesticides, and antibiotic treatments). This would send the right signals to farmers and would legitimize an extended use of the provider gets principle, allowing the remuneration of positive externalities. Demand measures should favor the adoption of healthier and environmentally friendly food diets by changing consumer behaviors through dietary recommendations, information campaigns, nutritional labeling, and fiscal instruments.