Measurement

This page provides the following information:

This page provides an overview of how household food security and food insecurity are measured. For detailed technical information on measurement methods, questionnaires, and calculating food security scales, see Food Security in the U.S.: Survey Tools.

What Is Food Security?

Food security for a household means access by all members at all times to enough food for an active, healthy life. Food security includes at a minimum:

  • The ready availability of nutritionally adequate and safe foods.
  • Assured ability to acquire acceptable foods in socially acceptable ways (that is, without resorting to emergency food supplies, scavenging, stealing, or other coping strategies).

...and Food Insecurity?

Food insecurity is the limited or uncertain availability of nutritionally adequate and safe foods, or limited or uncertain ability to acquire acceptable foods in socially acceptable ways.

(Definitions are from the Life Sciences Research Office, S.A. Andersen, ed., "Core Indicators of Nutritional State for Difficult to Sample Populations," The Journal of Nutrition 120:1557S-1600S, 1990.)

Does USDA Measure Hunger?

USDA does not have a measure of hunger or the number of hungry people. Prior to 2006, USDA described households with very low food security as "food insecure with hunger" and characterized them as households in which one or more people were hungry at times during the year because they could not afford enough food. "Hunger" in that description referred to "the uneasy or painful sensation caused by lack of food."

In 2006, USDA introduced the new description "very low food security" to replace "food insecurity with hunger,"—recognizing more explicitly that, although hunger is related to food insecurity, hunger is a different phenomenon. Food insecurity is a household-level economic and social condition of limited access to food, while hunger is an individual-level physiological condition that may result from food insecurity.

Information about the incidence of hunger is of considerable interest and potential value for policy and program design. But providing precise and useful information about hunger is hampered by the lack of a consistent meaning of the word. "Hunger" is understood variously by different people to refer to conditions across a broad range of severity, from rather mild food insecurity to prolonged clinical undernutrition.

USDA sought guidance from the Committee on National Statistics (CNSTAT) of the National Academies on the use of the word "hunger" in connection with food insecurity. The independent panel of experts convened by CNSTAT concluded that in official statistics, resource-constrained hunger (i.e., physiological hunger resulting from food insecurity) "...should refer to a potential consequence of food insecurity that, because of prolonged, involuntary lack of food, results in discomfort, illness, weakness, or pain that goes beyond the usual uneasy sensation."

Validated methods have not yet been developed to measure resource-constrained hunger in this sense, in the context of U.S. conditions. Such measurement would require the collection of more detailed and extensive information on physiological experiences of individual household members than could be accomplished effectively in the context of USDA's annual household food security survey.

USDA's measurement of food insecurity, then, provides some information about the economic and social contexts that may lead to hunger but does not assess the extent to which hunger actually ensues.

How are Food Security and Insecurity Measured?

The food security status of each household lies somewhere along a continuum extending from high food security to very low food security. This continuum is divided into four ranges, characterized as follows:

  1. High food securityHouseholds had no problems, or anxiety about, consistently accessing adequate food.

  2. Marginal food security—Households had problems at times, or anxiety about, accessing adequate food, but the quality, variety, and quantity of their food intake were not substantially reduced.

  3. Low food security—Households reduced the quality, variety, and desirability of their diets, but the quantity of food intake and normal eating patterns were not substantially disrupted.

  4. Very low food security—At times during the year, eating patterns of one or more household members were disrupted and food intake reduced because the household lacked money and other resources for food.

USDA introduced the above labels for ranges of food security in 2006. See Food Security in the U.S.: Definitions of Food Security for further information.

For most reporting purposes, USDA describes households with high or marginal food security as food secure and those with low or very low food security as food insecure.

Placement on this continuum is determined by the household's responses to a series of questions about behaviors and experiences associated with difficulty in meeting food needs. The questions cover a wide range of severity of food insecurity.

Least severe:
Was this statement often, sometimes, or never true for you in the last 12 months? "We worried whether our food would run out before we got money to buy more."

Somewhat more severe:
Was this statement often, sometimes, or never true for you in the last 12 months? "We couldn't afford to eat balanced meals."

Midrange severity:
In the last 12 months, did you ever cut the size of your meals or skip meals because there wasn't enough money for food?

Most severe:
In the last 12 months, did you ever not eat for a whole day because there wasn't enough money for food?

In the last 12 months, did any of the children ever not eat for a whole day because there wasn't enough money for food?

Every question specifies the period (last 12 months) and specifies lack of resources as the reason for the behavior or experience ("we couldn't afford more food," "there was not enough money for food.")

Food Insecure. Households that report three or more conditions that indicate food insecurity are classified as "food insecure." That is, they were at times unable to acquire adequate food for one or more household members because they had insufficient money and other resources for food. The three least severe conditions that would result in a household being classified as food insecure are:

  • They worried whether their food would run out before they got money to buy more.
  • The food they bought didn't last, and they didn't have money to get more.
  • They couldn't afford to eat balanced meals.

Households are also classified as food insecure if they report any combination of three or more conditions, including any more severe conditions.

Very Low Food Security. Households having "very low food security" were food insecure to the extent that eating patterns of one or more household members were disrupted and their food intake reduced, at least some time during the year, because they could not afford enough food. To be classified as having "very low food security," households with no children present must report at least the three conditions listed above and also that:

  • Adults ate less than they felt they should.
  • Adults cut the size of meals or skipped meals and did so in 3 or more months.

Many report additional, more severe experiences and behaviors as well. If there are children in the household, their experiences and behaviors are also assessed, and an additional two affirmative responses are required for a classification of very low food security.


Survey Questions Used by USDA to Assess Household Food Security

1. "We worried whether our food would run out before we got money to buy more." Was that often, sometimes, or never true for you in the last 12 months?

2. "The food that we bought just didn't last and we didn't have money to get more." Was that often, sometimes, or never true for you in the last 12 months?

3. "We couldn't afford to eat balanced meals." Was that often, sometimes, or never true for you in the last 12 months?

4. In the last 12 months, did you or other adults in the household ever cut the size of your meals or skip meals because there wasn't enough money for food? (Yes/No)

5. (If yes to question 4) How often did this happen—almost every month, some months but not every month, or in only 1 or 2 months?

6. In the last 12 months, did you ever eat less than you felt you should because there wasn't enough money for food? (Yes/No)

7. In the last 12 months, were you ever hungry, but didn't eat, because there wasn't enough money for food? (Yes/No)

8. In the last 12 months, did you lose weight because there wasn't enough money for food? (Yes/No)

9. In the last 12 months did you or other adults in your household ever not eat for a whole day because there wasn't enough money for food? (Yes/No)

10. (If yes to question 9) How often did this happen—almost every month, some months but not every month, or in only 1 or 2 months?

(Questions 11-18 were asked only if the household included children age 0-17)

11. "We relied on only a few kinds of low-cost food to feed our children because we were running out of money to buy food." Was that often, sometimes, or never true for you in the last 12 months?

12. "We couldn't feed our children a balanced meal, because we couldn't afford that." Was that often, sometimes, or never true for you in the last 12 months?

13. "The children were not eating enough because we just couldn't afford enough food." Was that often, sometimes, or never true for you in the last 12 months?

14. In the last 12 months, did you ever cut the size of any of the children's meals because there wasn't enough money for food? (Yes/No)

15. In the last 12 months, were the children ever hungry but you just couldn't afford more food? (Yes/No)

16. In the last 12 months, did any of the children ever skip a meal because there wasn't enough money for food? (Yes/No)

17. (If yes to question 16) How often did this happen—almost every month, some months but not every month, or in only 1 or 2 months?

18. In the last 12 months did any of the children ever not eat for a whole day because there wasn't enough money for food? (Yes/No)
 


How Many Households are Interviewed in the National Food Security Surveys?

USDA's food security statistics are based on a national food security survey conducted as an annual supplement to the monthly Current Population Survey (CPS). The CPS is a nationally representative survey conducted by the Bureau of the Census for the Bureau of Labor Statistics. The CPS provides data for the Nation's monthly unemployment statistics, and annual income and poverty statistics.

In December of each year, after completing the labor force interview, about 40,000 households respond to the food security questions—and to questions about food spending and about the use of Federal and community food assistance programs. The households interviewed in the CPS are selected to be representative of all civilian households at State and national levels.


What is “Food Insufficiency”?

Food insufficiency is a measure of food adequacy that has been fielded in Federal surveys for many years. Food insufficiency is included in the Census Bureau’s Household Pulse Survey (HPS) to assess the Nation's well-being during the COVID-19 pandemic in 2020 and 2021. ERS collaborated with the Census Bureau and other Federal statistical agencies to create the survey. Food insufficiency is related to the concept of food insecurity used as a measure of well-being in the United States for the past 25 years. Food insecurity is monitored annually in the ERS report series Household Food Security in the United States. Below we explain and compare the measures of food insufficiency and food insecurity.

Food insecurity means that households were, at times, unable to acquire adequate food for one or more household members because the households had insufficient money and other resources for food. Food insecurity is measured at two levels of severity:

  • Low food security: Food-insecure households classified as having low food security have reported reduced diet quality and variety—but typically have reported fewer, if any, indications of reduced food intake.
  • Very low food security: Food-insecure households in the more severe range of food insecurity, classified as having very low food security, have reported multiple indications of reduced food intake and disrupted eating patterns, such as skipping meals.

In 2020, 10.5 percent of U.S. households were food insecure, and 3.9 percent of households experienced very low food security.

Household Food Security in the United States in 2020

Annual food security statistics come from the Current Population Survey Food Security Supplement (CPS-FSS) data. Food insecurity status is assigned based on responses to the full household food security survey module. The module includes a series of 10 items for households without children and 18 items for households with children. (See Food Security in the US for more information on food insecurity.)

Food insufficiency means that households sometimes or often did not have enough to eat. In the HPS, food insufficiency is measured in the last 7 days. The HPS was first fielded in April 2020, and continuing into 2021. HPS was designed to collect near real-time information on the well-being of the U.S. population during the COVID-19 pandemic. It was intended to assess rapid changes over time and was designed as an internet survey with weekly or biweekly data collections. The survey covers many different topics, and the goal to keep the survey burden as low as possible necessitated succinct measures. Therefore, a single food sufficiency survey item was used in the HPS rather than the full food security survey module included in the CPS-FSS. While the full food security measure offers a more precise and detailed indicator, the advantage of the food insufficiency question is that it is short, as well as being easy to administer and interpret. The characteristics of food insufficiency are compared with the characteristics of food insecurity in the section below, “Comparing food insufficiency versus food security."

There is significant overlap between food insecurity and food insufficiency. The CPS-FSS includes all the survey items that comprise the household food security measure and the food insufficiency survey items. The inclusion of all items in one survey enables an examination of the overlap between food insufficiency and food insecurity. In recent years of the CPS-FSS data, the majority of households classified as food secure were also classified as food sufficient. Most households classified as having low food security were also classified as having marginal food sufficiency. Among households with very low food security nearly half were classified as having low or very low food sufficiency. This same cross-tabulation is not available with the HPS data because the HPS does not include a measure of food insecurity. Nevertheless, understanding how food insecurity and food insufficiency overlap in the CPS-FSS data is informative for interpreting food insufficiency statistics during the COVID-19 pandemic.

According to the HPS, the prevalence of food insufficiency (low and very low food sufficiency) among U.S. adults rose—from 9.5 percent as of April 23, 2020 to 13.4 percent as of December 21, 2020—before declining to 8.0 percent as of April 26, 2021. Food insufficiency, as measured in the December 2020 CPS-FSS, was 3.5 percent compared with 3.7 percent in December 2019.

Readers may wonder why the HPS findings on food insufficiency differ considerably from the CPS-FSS and some other surveys. Response rates differ substantially between the HPS and CPS-FSS. In 2020, about 76 percent of CPS respondents also completed the FSS interview. Response rates varied across weeks of the HPS data collection, from 1 percent to 10 percent. The much lower response rates to the HPS could have resulted in non-response bias that was not mitigated by weighting the sample based on observable characteristics. In addition to nonresponse, other factors could impact estimates from the HPS. More research is needed to understand how differences in response rates, sampling frame and methods, survey mode, survey content, and other differences between the surveys may have affected estimates from the HPS and CPS-FSS.

Another major difference between the HPS and CPS-FSS data is the reference period used in the food sufficiency question. The HPS food insufficiency item asks respondents to assess what best describes their food situation in the last 7 days, while the CPS-FSS food insufficiency item asks respondents to assess what best describes their food situation in the last 12 months (as specified in the lead-in to the question). Respondents may accurately give different responses to this question based on different reference periods. A respondent may believe that they did not have enough to eat during a 7-day period, but when reflecting on the last 12 months, may believe that what best describes the entire period is that they had enough to eat. This is an important difference, in that the full food security measure refers to the most severe food hardship a household experiences over the course of the year, since the questions ask if respondents “ever” or “sometimes” experienced specific food hardships. Meanwhile, the food insufficiency question asks what “best describes” a household’s food situation as a whole, not what the household’s worst food hardship might have been. The HPS is the first Federal survey to include the food insufficiency question with a 7-day reference period, so there is no research at the time of writing to understand how short-term versus long-term reporting of food insufficiency may differ. More research is needed to understand the timing of any food hardships experienced in 2020—and how respondents may have reported food hardships across different surveys, different measures, and different reference periods.

To learn more about food insufficiency and food insecurity during the COVID-19 pandemic, see the box labeled “Understanding Differences in 2020 Food Hardship Estimates” in the most recent annual report.

Household Food Security in the United States in 2020

Comparing food insufficiency, as measured in the HPS, versus food insecurity measures

Definitions

  • Food insufficiency
    • Marginal food sufficiency: A household reports they had enough to eat but not always the kinds of food they wanted to eat in the last 7 days.
    • Food insufficiency: A household did not have enough to eat, sometimes or often, in the last 7 days.
      • Low food sufficiency: A household did not have enough to eat sometimes in the last 7 days.
      • Very low food sufficiency: A household did not have enough to eat often in the last 7 days.
  • Food insecurity: A household was unable to acquire adequate food because they had insufficient money and other resources for food.
    • Low food security: food insecurity characterized primarily by reductions in dietary quality and variety.
    • Very low food security: food insecure to the extent that eating patterns were disrupted (skipped meals) and food intake reduced because the household could not afford enough food.

Survey question(s)

  • Food insufficiency: Single question asking, “In the last 7 days, which of these statements best describes the food eaten in your household? Select only one answer: 1)Enough of the kinds of food (I/we) wanted to eat; 2) Enough, but not always the kinds of food (I/we) wanted to eat; 3) Sometimes not enough to eat; 4)Often not enough to eat.” Responses of (3) or (4) are classified as food insufficient.
  • Food insecurity: A scale that consists of 10 survey questions for all households and an additional 8 questions for households with children. The questions cover a range of severity of conditions and behaviors that characterize food insecurity. Households that affirm 3 items are classified as food insecure. Adult- only households that affirm 6 items, and households with children that affirm 8 items, are classified as very low food secure.

Reference period

  • Food insufficiency: Last 7 days
  • Food insecurity: 12 months or 30 days

Characteristics of food hardship experienced

  • Food insufficiency: The food insufficiency question provides relatively little detail on the food hardship experienced and indicates only whether a household had enough to eat. Food insufficiency is a more severe condition than food insecurity and measures whether a household generally has enough to eat. In this way, food insufficiency is closer in severity to very low food security than to overall food insecurity.
  • Food insecurity: Since the food security measure uses multiple items, it covers households worrying about food running out, dietary quality and variety, and quantity of food consumed. Food insecurity is measured at two levels of severity. In households with low food security, the hardships experienced are primarily reductions in dietary quality and variety. In households with very low food security, the hardships experienced are reduced food intake and skipped meals.