Valid assessment is the foundation on which effective interventions and programmes can be built to alleviate hunger and reduce the number of undernourished people. In 1996, the Director General urged "member countries to assign a high priority to the collection and provision of basic data".

This spurred the creation of Food Insecurity and Vulnerability Information and Mapping Systems (FIVIMS), an inter-agency working group (IAWG) initiative to promote the development of national and international networks of systems that assemble, analyse and disseminate information about the problems of food insecurity and vulnerability, to support improved action. The fundamental goals of FIVIMS are to enhance the use of existing national data, to help in developing networks, and to promote capacity-building at local level.

The State of Food Insecurity in the World (SOFI) presents the progress towards ending hunger. SOFI provides FAO's most recent estimates of the prevalence of undernourishment and the numbers of undernourished people in many countries, based on FAO methodology. It reports on global and national efforts and performances to reduce the number of undernourished. The report also focuses on three questions : who are the food insecure, where are they located, why are they food insecure?

FAO's statistical databases present data on foods available for human consumption. National supplies are expressed as amounts of foods (kg per caput/year), and as Dietary Energy Supply (kcal per caput/day), Dietary Protein and Dietary Fat Supply (g per caput/day). The data are used to estimate the prevalence of undernourishment, and the trends in prevalence, but they also provide valuable information on food patterns and trends, and on diet diversification.

The nutritional status of individuals is commonly evaluated through the use of anthropometry. Anthropometric measurements are used as outcome indicators that reflect the end result of all the factors that affect nutritional status. Undernutrition in children, encompassing stunting, wasting and underweight, a low body mass index in adolescents and adults, are some of the major consequences of energy and nutrient deficits. Excessive energy intake, on the other hand, leads to overweight, obesity and co-morbidities, an issue being increasingly addressed.