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. Three conditions must be fulfilled to ensure food security: food must be available, each person must have access to it, and the food utilized must fulfill nutritional requirements.

  • 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 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, transfer 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 consumption and access in 76 low- and middle-income countries39 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 go out 10 years. Projections of food gaps for the countries are based on differences between a nutritional target and estimates of food availability, which is domestic food supply (production plus commercial imports) minus nonfood use. The estimated food gap (distribution gap) are 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 in the International Food Security Assessment 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. In the ERS international food security model, the total projected amount of available food is allocated among different income groups using income distribution data.

What is the World Food Summit?

In November 1996, world leaders assembled in Rome for the World Food Summit to renew global commitment to the fight against hunger. The United Nations Food and Agriculture Organization (FAO) called the Summit in response to widespread undernutrition and growing concern about the capacity of agriculture to meet future food needs. Participants at the summit pledged by 2015 to reduce the current number of hungry people by half.

FAO monitors efforts related to, and progress made toward, meeting the goal of the World Food Summit.

Do ERS and the Food and Agricultural Organization (FAO) use different measurements to assess global food security?

To estimate the number of hungry people at the country level, both ERS and FAO start by calculating the total amount of food (food availability), taking into account food production, changes in stocks, and imports as presented in the food balance sheet. While FAO uses the number of calories as a unit of measurement, ERS converts the calories to kilograms of grain equivalent.

To establish the number of people consuming less than the nutritional target, it is first necessary to determine consumption inequality due to inequality in purchasing power, i.e., access to food. FAO uses the estimate of per capita calorie consumption of a country as its mean, while consumption/income variance is estimated based on household survey data; it assumes the consumption/income relationship to be log-normal. ERS estimates of the consumption/income relationship are based on cross-country data on per capita calorie consumption and per capita income, using a semi-log regression functional form. ERS uses the estimated coefficients to determine consumption/income elasticity for each country. Income distribution data from the World Bank and the estimated income elasticity coefficients are then used to determine food consumption for each income group by country.

Once consumption inequality has been determined, a food level has to be established below which people are considered undernourished, i.e., suffer from hunger. FAO bases its cutoff food level on a minimum calorie requirement of approximately 1,800 calories on average per capita per day for all countries. ERS uses a higher level of roughly 2,100 calories per day as the average per capita target for all countries. Once the threshold level is established, the number of people living in hunger is calculated.

For further information, UN FAO State of Food Insecurity 2012 describes FAO methodology in detail. ERS publishes its methodology in its annual International Food Security Assessment report.

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 developing countries, a large part of the population lives in poverty, which is sometimes grave enough to cause death by starvation. National food supplies are at times insufficient to feed the entire population, even if the food available were distributed evenly among all citizens. ERS research focuses on food availability and access by using food production, trade, and macroeconomic data.

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. The focus is on access to food and food utilization, while in the United States general food availability is of little concern.