Questions & Answers



What is food security?

Food security is the ability of all people at all times to access enough food for an active and healthy life. Four conditions must be fulfilled to ensure food security: food must be available, each person must have access to it, the food utilized must fulfill nutritional requirements, and there needs to be stability in food access and availability.

  • Availability. Global food security requires sufficient food production to provide the world's people with the amount of food they need to lead active and healthy lives. On a national level, food can be produced domestically or imported. Domestic production depends on the size of the area harvested and the yields achieved and is heavily influenced by weather, especially where irrigation is nonexistent. Imports depend on a country's ability to finance them and are determined by export earnings and international food prices. Domestic production and import activity are also affected by domestic policies and international prices.
  • Access. Access to food is mainly determined by household income. Lack of access is therefore closely linked with poverty. Where incomes are insufficient, transfers or food assistance programs (such as feeding programs or food subsidies) are a means to ensuring access to food.
  • Utilization. Adequate food utilization is a key component of food security. Access to safe water, good sanitation, and basic health care make a difference in nutritional well-being as they have an impact on the body's ability to utilize consumed foods. Inadequate knowledge of basic nutritional facts may also prevent the best use of available food.
  • Stability. To be food secure, a population, household or individual must have access to adequate food at all times. They should not risk losing access to food as a consequence of sudden shocks (e.g. an economic or climatic crisis) or cyclical events (e.g. seasonal food insecurity). The concept of stability can therefore refer to both the availability and access dimensions of food security.

How is food security assessed?

The ERS international food security model projects food demand and access in 76 low- and middle-income countries—39 in Sub-Saharan Africa, 4 in North Africa, 11 in Latin America and the Caribbean, and 22 in Asia. Commodity coverage in the model includes grains, root crops, and a group called "other." The three commodity groups in total account for 100 percent of all calories consumed in the study countries. The projections are based on the most recently available 3-year average of data and cover 10 years. Projections of food gaps for the countries are based on differences between a nutritional target and estimates of food demand. The estimated food gap (distribution gap) is used to evaluate food security of the countries. Finally, based on projected population, the number of people unable to meet the nutritional target is projected. The methodology appendix on the new demand-oriented model in the

International Food Security Assessment, 2016-26

report describes the ERS approach in more detail.

What is a distribution gap?

A distribution gap measures the difference between projected food consumption and the amount of food needed to increase consumption in food-deficit income groups within individual countries to meet the nutritional target. Inadequate economic access to food is the major cause of chronic undernutrition in developing countries and is related to the level of income and food prices. 

How do IFSA results compare to other food security assessments?

The International Food Policy Research Institute’s (IFPRI’s) Hunger Index and FAO’s annual flagship publication, The State of Food Insecurity in the World (SOFI)—jointly prepared by the Food and Agriculture Organization of the United Nations (FAO), the International Fund for Agricultural Development (IFAD) and the World Food Program (WFP)—both publish prevalence of undernourishment for most countries in the world. Their assessments are the average for the most recent 3 years, while IFSA provides annual measures for the current year and projections 10 years out.

Because much of the IFSA is based on FAO data such as food production, trade, and use data, IFSA and SOFI results tend to be similar. Furthermore, the IFSA uses SOFI’s consumption distribution: the functional form, and the coefficient of variation that describes in more detail how consumption is distributed across the entire population.  However, assumptions about macroeconomic conditions are different. FAO uses UN sources for population and GDP/income growth; IFSA uses USDA international macro data, which use U.S. census data as its source for international population data.  Furthermore, given that assessments are prepared at different times, macroeconomic assumptions differ accordingly.

SOFI’s prevalence of undernourishment measure indicates the likelihood that a person in a given country finds herself food insecure, as measured against the minimum dietary energy requirement (MDER), or the amount of energy needed for light activity and minimum acceptable weight for attained height. The MDER differs by country as it depends on demographic, cultural, geographic, and climatic conditions within each country. This target is between 1,700 and 1,900 kcal per capita per day (the world average for 2014-16 is 1,844). The USDA/ERS IFSA report uses 2,100 kcal per capita per day as a nutritional target, which is the average amount of energy needed to sustain a moderate level of activity.

Given differences in methodology and nutritional targets, it is difficult and possibly inappropriate to directly compare results across studies.

How does ERS research on international food security differ from its research on food security in the United States?

ERS research on international food security is based on measurable components of food supply at the national level. In many developing countries, a large part of the population lives in poverty, which is sometimes grave enough to cause death by starvation. Insufficient incomes or high food prices—possibly due to scarce supply—can be the cause of food insecurity. ERS research uses available income and food price data or computational methods to assess food access across the entire income spectrum of each country.

ERS research on Food Security in the United States is based on household surveys that capture householders' subjective evaluations of their food security. In wealthier countries such as the United States, where total food supplies are more than sufficient to feed the entire population, famine or starvation is not a threat. However, even in the United States, a large number of people are poor and suffer from hunger due to inadequate incomes. Research on food security tries to understand the true extent of the problem, as well as the underlying causes. In the United States and increasingly in most countries of the world food availability at the national level is sufficient. The focus is instead on access to food and food utilization.

Last updated: Monday, January 30, 2017

For more information contact: Birgit Meade and Karen Thome

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