Economics represents one of the four dimensions of sustainable nutrition. Affordable nutrient density is a key indicator of access to sustainable healthy diets. While the nutritional value of foods is assessed using nutrient density metrics, affordability metrics assess energy content and nutritional value of foods in relation to their cost. To be nutrition-relevant, such economic indicators are normally expressed in terms of monetary cost per calorie or per nutrient, as opposed to food weight. Affordability of healthy foods can also be related to the relative cost of staple grains and linked to local wages, incomes, and community purchasing power. The same concepts can be extended to the carbon cost of food production. In parallel with the affordability metrics, greenhouse gas emissions and other environmental costs ought to be calculated per 1000 kcal or per nutrient rather than per kilogram of food. Foods and food patterns need to be nutrient-rich, affordable, culturally appropriate, and appealing, and with low impact on natural resources. In this perspective article, we critically reflect on the linkages between the economic and health dimensions of sustainable nutrition and discuss some of the inherent tensions and synergies among them. Finally, we propose an approach to better integrate economic and sustainability considerations in the nutrition policy. Policy goals should prioritize balancing the nutritional value of food against its monetary or environmental cost.