How is malnutrition mapped and measured globally?

Malnutrition is mapped and measured globally through indicators such as stunting, wasting, and underweight prevalence in children under five.

To understand the global scale of malnutrition, various indicators are used. These indicators are primarily focused on children under the age of five, as this is a critical period for growth and development. The three main indicators used are stunting (low height for age), wasting (low weight for height), and underweight (low weight for age). These indicators are used to assess the nutritional status of children and provide a snapshot of the severity of malnutrition in a given population.

Stunting is a measure of chronic malnutrition and reflects a failure to receive adequate nutrition over a long period. It is calculated by comparing a child's height to the World Health Organisation's (WHO) child growth standards. Children who fall below minus two standard deviations from the median of the WHO's reference population are considered stunted.

Wasting, on the other hand, is a measure of acute malnutrition and indicates a recent and severe process of weight loss, often associated with acute starvation and/or severe disease. Like stunting, it is calculated by comparing a child's weight for height to the WHO's child growth standards. Children who fall below minus two standard deviations from the median of the WHO's reference population are considered wasted.

The underweight indicator combines elements of both stunting and wasting, providing a broad measure of undernutrition. It is calculated by comparing a child's weight for age to the WHO's child growth standards. Children who fall below minus two standard deviations from the median of the WHO's reference population are considered underweight.

These indicators are collected through national surveys, such as the Demographic and Health Surveys (DHS) and the Multiple Indicator Cluster Surveys (MICS), which are conducted in many low and middle-income countries. The data collected is then used to create global maps of malnutrition, highlighting areas of high prevalence and identifying trends over time. These maps are crucial tools for policymakers and aid organisations, helping to target interventions and monitor progress in the fight against malnutrition.