Food and nutrition assessments, combined with expenditure surveys, provide information about what people eat, how much money they spend on it, and their nutritional status. Additionally, individuals’ nutrient needs are known, and households are advised on how to ensure consumption of a healthy and nutritious diet. However, in contexts where food availability does not appear to be a problem, it remains unknown how much of the nutrient gap is due to economic constraints to a nutritious diet (unaffordability), a lack of knowledge on healthy eating, and food and nutrition practices. Moreover, current methodologies to assess food and nutrition security are not able to analyse households' constraints in accessing their nutrient requirements, especially for their most vulnerable members, such as children under two years.
The Minimum Cost of a Nutritious Diet (CoD) is the cost of a theoretical, simulated diet (food basket) which satisfies all nutritional requirements of a modelled family at the minimal possible cost, based on the availability, price, and nutrient content of local foods. Any other food basket at the same price will be less nutritious, and any other food basket of the same nutrient value will be more expensive. Hence, when combined with household income and expenditure data, the CoD can be used to estimate the proportion of households that can afford an adequately nutritious diet in a particular area. Therefore, the CoD is a tool to link nutrient availability with economic food access.