Methods and Metrics for Food Security and Nutrition Outcome Indicators

Agriculture influences food production, food is a component of diets, and diets influence nutritional status. Agricultural policies and interventions impact nutritional outcomes by through several pathways that influence the quantity and quality of food consumed by individuals. Nutritional outcomes, usually assessed by physical measurements (anthropometry), are measured at the individual level, as they relate to what an individual consumes and the process of absorbing and utilizing nutrients within the body (Aberman et al., 2015). A nutrition-sensitive intervention aims to contribute to better nutritional outcomes by addressing the underlying determinants of malnutrition such as access to safe and nutritious foods (quantity and quality/diversity), adequate care and a healthy and hygienic environment. Dietary quality is a key intermediary between agriculture and nutrition. Individual dietary quality is best measured by dietary diversity, which is a measure of nutritional adequacy. This means that agriculture interventions and policies, designed to increase food production, only address one aspect of food security (FS). Thus, the appropriate indicator needs to be selected to determine the impact of agriculture on nutrition. For example, an agricultural intervention that only addresses the availability of food, the lack of which manifests as hunger or acute malnutrition, will most likely be assessing wasting or weight-for-height (a nutritional status indicator) as this is the most appropriate nutritional outcome related to increases in household food availability. However, a different nutritional outcome indicator will be required when the interest of the intervention is to improve diet quality. In this case, a better nutritional outcome is stunting, assessed by height for-age. For an agricultural intervention, e.g., biofortification, where improvements made in the food system are reflected in the increased micronutrient content of food (e.g., Vitamin A content in orange-flesh sweet potatoes), a biochemical metric of nutritional status rather than anthropometry might be necessary. While nutrition sensitive, consumption data alone are not a nutrition indicator because it does not directly lead to improved nutritional outcomes. The objective of this paper is to describe existing and current metrics for assessing food security and nutritional status outcomes. This review looks at different metrics, especially ones that are more relevant to developing food security measures, diet quality and nutritional status.