Monitoring of food affordability and diet quality


This presentation was delivered by Anna Herforth, Ph.D., Adjunct Associate Research Scientist at the Agriculture and Food Security Center of the Earth Institute at Columbia University.

This presentation begins with the question of how to define a  healthy diet, which is the basis for subsequent discussion about how to measure (a) diet quality and (b) cost of healthy diets. A question of major importance to public health nutrition is how food environments (including food prices) affect diet quality, and how each can be improved, but the discussion is hampered by the fact that we have little data on either.

Diet quality is the largest risk factor in the global burden of disease, and the common factor among malnutrition in all its forms. To date, however, no internationally comparable indicators of diet quality are measured across countries. Gallup, Inc., has proposed to develop a diet quality (DQ) module to include in the Gallup World Poll, which is implemented in 160 countries. Ideally, such a module would be simple to administer, yield indicators that are easy to interpret and reflect multiple facets of DQ, and be comparable across countries.

A review of international and national definitions of diet quality yielded a set of elements of healthy diets that appear to be consistent and important across all regions of the world. Development of the module will use these elements are the basis for indicators that would capture both "adequacy" and "moderation" components of diet quality. A DQ module would enable tracking of trends over time, better information for policy and program formulation, and analyses about the causes and consequences of poor (or healthy) diets.

Food prices are a major determinant of food choice and dietary quality. While food prices are a topic of much international discourse and analysis, the basket of foods tracked typically consists of staple foods or economically important commodities, and bears little relationship to the cost of healthy diets. Therefore the food price indicators currently in use are not fit for purpose to understand the impact of policies and time trends on the cost of healthy diets.

The IANDA Project uses existing food price monitoring systems to reflect the cost of nutritious diets. Working in Ghana and Tanzania, we have piloted four indicators: Cost of Nutrient Adequacy (CoNA), Cost of Recommended Diets (CoRD), Cost of Diet Diversity (CoDD), and a Nutritious Food Price Index (NFPI). The central innovation of these indicators is that they are designed to use existing data, and therefore could be rapidly scaled up and compared across countries. Such indicators can better inform research, discourse, and action on how to increase access to nutritious diets.

This presentation was part of at an event titled "Aligning the Food System to Meet Dietary Needs: Fruits and Vegetables," which took place on June 2-3, 2017, at the UC Davis Conference Center.