Measurement of household insecurity
How is household food insecurity measured in national surveys?
Routine monitoring in a national household survey is important for quantifying the scale of food insecurity in the population, tracking how the problem changes over time, and identifying vulnerable groups.
Scales capturing self-reported experiences of food insecurity have been validated in different populations around the world. A commonly used scale, and variations of it, is the USDA Household Food Security Survey Module. This is used routinely in the U.S. and Canada, and has also been used in population-based surveys in the UK, including the Low Income Diet and Nutrition Survey and the Food and You Survey. The USDA module has also been used in other research studies, such as the Southampton Women’s study, Born in Bradford cohort study, and studies of people using food banks in London and across the UK.
The Household Food Security Module can be shortened by only including questions that reference adults and household members, removing questions that reference children, or shortened to six questions rather than the 10 questions found in the Adult Food Security Module. The questions can be asked with reference to different time periods. In the US, questions are asked in reference to both 12 months and the past 30 days in their annual Current Population Survey, giving an indication of how transient food insecurity is in the population. In 2019, the USDA Adult Food Security Survey Module, with a 30-day reference period, was added to the Family Resources Survey in the UK.
In 2019, the Food and Agriculture Organisation launched a programme of research into household food insecurity around the world, exploring the use of an experience-based measure based on the USDA scale. It is simpler, consisting of only 8 questions with simple yes/no responses. It doesn’t ask parents/guardians about child experiences, and it doesn’t capture how frequently households had experiences over the past twelve months, but through its administration in the Gallup World Poll, comparable estimates for food insecurity are now available for countries around the world.
One thing that is important to consider when using these scales is the threshold for food insecurity. In Canada, the PROOF research team has highlighted that marginal food insecurity is an important experience to specify in research on food insecurity – this is when households respond affirmatively to only one question. Thresholds for food insecurity also differ between Canada and the United States because Canada considers two or more items on either the adult or child scale as moderate food insecurity, whereas the United States only classes someone as food insecure if three or more questions on either scale is indicated. Confused? Probably, but being aware of different thresholds is important because it means prevalence estimates may not be comparable between countries. For a quick guide, see this webinar by the PROOF team.
Thresholds set by the FAO using Gallup World Poll data are even harder to understand. They use calibrating methods to scale responses relative to a global reference scale to enable comparisons between countries. This means it is not quite as easy as counting up affirmative responses. If countries choose to use the FIES, they should use their own thresholds, accounting for the response pattern in the population. But any indication of food insecurity should be reported. This is not currently done for the FAO data, and their threshold for moderate food insecurity is for more severe conditions than Canada and the United States. It roughly equates to where households indicate a minimum of five responses on their scale.
Importantly, any measurement tool should include multiple items that range in severity. This is because research has shown that some people might experience some manifestations of food insecurity but not others. All items in the measurement module map on to an underlying construct of food insecurity, but no single item is sufficient to capture this.
What are some limitations of measuring and monitoring household food insecurity in a national survey?
Some groups are left out of household surveys, such as people with no fixed address, so any household survey is likely going to underestimate food insecurity in the population if groups who are particularly vulnerable are not included.
Others have been concerned that the measurement tool may not capture all household experiences. The operational definition of household food insecurity, that is, what is captured by measurement tools is “insecure and insufficient food due to financial constraints”.
The scale sets a threshold – marginal experiences mean being worried about food running out or changing one’s diet because there isn’t enough money for food. Other types of food compromises are not a part of food insecurity measurement, such as sticking more closely to a household food budget or inviting friends over for a meal less often.
In light of the rapid rise of food bank use, from a policy and practice perspective, there is particular concern about households not having enough money for food in the UK. This is what measurement scales have been designed to capture. So using a measurement framework, scales that measure food insecurity have been designed to have high sensitivity to capturing people at risk of not having enough food – that is, if someone affirms a response on the food insecurity scale, they are likely to be correctly identified as food insecure. People with less severe experiences of changing their food purchasing or food habits are not going to answer questions affirmatively.
Why should we measure food insecurity and not just poverty?
Similar to the way that other measures of material hardship, covering housing conditions, bill and rent arrears, and the ability to heat one’s home are important part of measuring and tracking well-being in the population, so too is food insecurity. Lacking in basic essentials is a sign that income and other financial resources are not sufficient to meet basic needs.
Compared to income-based poverty measures based on annual income, household food insecurity is a more dynamic measure of poverty. Why is this? Likely because spending on food is self-regulated, meaning that when households feel stretched financially, spending on food is often among the first essential items that are cut back on. Compared to fixed contracts, payments that are automatically deducted from income, and the threat of eviction, research has shown household spending on food is often the most flexible.
Given the wider range of necessities to enable participation today (e.g. access to the Internet and a computer, mobile phones), updated research on how spending priorities are managed on low incomes is needed. However, in 2012, research from the Poverty and Social Exclusion survey highlighted a gradient of what poor households were doing without. Being unable to afford two meals a day was something experienced less often. Expenditure surveys suggest that when households are poor, multiple compromises are made, with reduced spending in all categories, including food, household bills, and social participation.
Box 1: The USDA Household Food Security Survey Module
These next questions are about the food eaten in your household in the last 12 months, since (current month) of last year and whether you were able to afford the food you need. | ||
Stage 1 Adult/Household questions In the last 12 months, can you tell me if these statements were true for you? |
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1 | “We worried whether our food would run out before we got money to buy more.” | Often true Sometimes true Never true |
2 | “The food that we bought just didn’t last, and we didn’t have money to get more.” | Often true Sometimes true Never true |
3 | “We couldn’t afford to eat balanced meals.” | Often true Sometimes true Never true |
Stage 2 Adult/Households questions (if one or more Stage 1 Adult/Household questions affirmed) In the last 12 months… |
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4a | Did (you/you or other adults in your household) ever cut the size of your meals or skip meals because there wasn’t enough money for food? | Yes No |
4b | If yes: How often did this happen—almost every month, some months but not every month, or in only 1 or 2 months? | Almost every month Some months but not every month Only 1 or 2 months |
5 | Did you ever eat less than you felt you should because there wasn’t enough money for food? | Yes No |
6 | Were you every hungry but didn’t eat because there wasn’t enough money for food? | Yes No |
7 | Did you lose weight because there wasn’t enough money for food? | Yes No |
Stage 3 Adult/Households questions (if one or more Stage 2 Adult/Household questions affirmed) In the last 12 months… |
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8a | Did (you/you or other adults in your household) ever not eat for a whole day because there wasn’t enough money for food? | Yes No |
8b | If yes: How often did this happen—almost every month, some months but not every month, or in only 1 or 2 months? | Almost every month Some months but not every month Only 1 or 2 months |
Stage 1 Child questions (posed only to households with children <18 years of age). Now I’m going to read you several statements that people have made about the food situation of their children. In the last 12 months, can you tell me if these statements were true for you? |
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1 | “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.” | Often true Sometimes true Never true |
2 | “We couldn’t feed our children a balanced meal, because we couldn’t afford that.” | Often true Sometimes true Never true |
3 | “The children were not eating enough because we just couldn’t afford enough food.” | Often true Sometimes true Never true |
Stage 2 Child questions (if one or more Stage 1 Child questions affirmed) In the past 12 months… |
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4 | Did you ever cut the size of any of the children’s meals because there wasn’t enough money for food? | Yes No |
5a | Did any of the children ever skip meals because there wasn’t enough money for food? | Yes No |
5b | How often did this happen? | Almost every month Some months but not every month Only 1 or 2 months |
Stage 3 Child questions (if one or more Stage 2 Child questions affirmed) In the past 12 months… |
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6a | Were the children ever hungry but you just couldn’t afford more food? | Yes No |
6b | Did any of the children ever not eat for a whole day because there wasn’t enough money for food? | Yes No |
Source: USDA ERS Survey Tools
Box 2: The Food and Agriculture Organisation Food Insecurity Experience Scale
Now I would like to ask you some questions about food. During the last 12 MONTHS, was there a time when… : | ||
1 | … you were worried you would not have enough food to eat because of a lack of money or other resources? | Yes No |
2 | … you were unable to eat healthy and nutritious food because of a lack of money or other resources? | Yes No |
3 | … you ate only a few kinds of foods because of a lack of money or other resources? | Yes No |
4 | … you had to skip a meal because there was not enough money or other resources to get food? | Yes No |
5 | … you ate less than you thought you should because of a lack of money or other resources? | Yes No |
6 | … your household ran out of food because of a lack of money or other resources? | Yes No |
7 | … you were hungry but did not eat because there was not enough money or other resources for food? | Yes No |
8 | … you went without eating for a whole day because of a lack of money or other resources? | Yes No |
Source: FAO The Food Experience Scale