The Prevalence of Undernourishment (PoU) is national-level model-based indicator used to understand food availability. It measures the percentage of the population whose dietary energy intake is below the Minimum Dietary Energy Requirement (MDER) for their age, sex, and height. It is calculated annually by the Food and Agriculture Organization (FAO) for each country, and is one of the indicators used to measure Goal 2 (End hunger, achieve food security and improve nutrition) of the Sustainable Development Goals. This indicator is used in the absence of data from individual dietary intake surveys.
Method of Construction
Because nationally-representative individual consumption data are not consistently available, the PoU relies upon a probability distribution model that uses a combination of national, household, and individual level data of food availability, access, distribution, and age/sex composition to estimate the overall level and distribution of calorie consumption in the population (Cafiero, 2014). The minimum dietary energy requirement (MDER) of the population is estimated based on a weighted average of the minimum requirements for each sex-age group in the population (Wanner et al. 2014). The prevalence of undernourishment is then calculated as the percentage of the population whose consumption falls below the MDER. The PoU indicator produced by the FAO is a three-year moving average. It is available on FAOSTAT as one of the indicators included in the Suite of Food Security Indicators, and is published annually in the State of Food Insecurity in the World report. For more detailed information on how data are collected, assumptions, and how calculations are completed by the FAO, please read the following report on measurements of hunger (Cafiero, 2014).
In addition, this indicator is one of several indicators included in the ADePT-FSM (Food Security Module) software package, which is a free standalone software developed by the FAO and the World Bank that allows users to easily derive food security indicators from household survey data. The software download and corresponding documentation can be found on the FAO website, here. Please also see the Moltedo et al. 2014 book published by the World Bank, which provides detailed instructions for analyzing food security using household survey data. See pages 58-59 in the Moltedo et al. document for details about how the ADePT software calculates the PoU.
PoU is an internationally recognized indicator, and is used by intergovernmental agencies, such as FAO and the World Food Programme (WFP), as well as non-governmental and governmental agencies. As mentioned above it is also one of the indicators for monitoring progress towards the second SDGs. It can help paint a picture of macro-level food availability trends, and given its widespread use for the past five decades, is useful in identifying national and global trends in population-level undernourishment (Jones et al., 2013). The PoU is also used to calculate the depth of food deficit indicator, which estimates the average per capita amount of additional energy (kcal) that undernourished individuals need to consume to reach their average dietary energy requirement (ADER). This indicator is part of the FAOSTAT Suite of Food Security Indicators and is published annually by FAO in the State of Food Insecurity (SOFI).
Strengths and Weaknesses
PoU data are publicly available and free to access on FAOSTAT. Along with ease of access, a clear strength of this indicator is that it has been calculated for almost every country in the world over decades, allowing for standardized comparisons over time and within and across countries. However, the PoU considers only energy intake, and alone it is not an appropriate indicator of malnutrition or dietary quality. In addition, as a three-year average, this indicator can be used as a measure of chronic hunger, but is unable to capture trends in undernourishment over shorter reference periods that may be associated with seasonality, price spikes, or climate-related shocks to the food system (Cafiero, 2014). Another drawback of the PoU is that its adequacy thresholds are based on MDER, which assumes low levels of physical activity and thus lower energy requirements than is likely to be realistic, according to some researchers (Lele et al., 2016).
Country-level prevalence of undernourishment is released each year by the FAO using data from their annual food balance sheet (FBS) data, adjusted using the most recent available Household Consumption and Expenditure Surveys (HCES).