Using anthropometry

Micronutrient surveys commonly include the assessment of nutritional status using anthropometry. Variables most often measured among children 0-59 months are: date of birth and date of visit (to calculate age), weight (in kilograms), and height/length 1 (in centimetres). These measurements are used to calculate weight-for-age (to assess underweight), height-for-age (to assess stunting), and weight-for-height (to assess wasting and overweight). The resulting z-scores 2 are compared to international standard reference ranges to assess an individual’s nutritional status. It is generally recommended to use the WHO Child Growth Standards as the reference ranges. 3,4 In some contexts, mid-upper arm circumference (MUAC) is measured in children 6–59 months of age, in addition to height/length and weight, to assess wasting.5

Among (non-pregnant) adult population groups, anthropometric measurements usually include height (in centimetres) and weight (in kilograms) to assess body mass index (BMI)6 and identify short stature.7 In addition to height and weight, MUAC is sometimes used as an indicator of nutritional status, however, height and weight are preferred since there are no global standards available for MUAC.8 In programmes or clinical settings, MUAC is mainly used for identifying wasting among pregnant women.9

More information on anthropometry assessment methods and the interpretation of results, along with associated tools, are discussed in Module 11, Data collection tools, field manual, and database, Module 12, Training and pilot testing, and Module 14, Data entry and cleaning.

  1. Height is measured among all population groups except children under 24 months of age, where length is measured. 

  2. z-score, or standard deviation-score = [observed value - median value of the reference population] / standard deviation value of reference population 

  3. The WHO Child Growth Standards [website]. Geneva: World Health Organization; 2019 http://www.who.int/childgrowth/standards/en/, accessed 20 March 2020). 

  4. Recommendations for data collection, analysis and reporting on anthropometric indicators in children under 5 years old. Geneva: World Health Organization and the United Nations Children’s Fund; 2019. Licence: CC BY-NC-SA 3.0 IGO https://apps.who.int/iris/bitstream/handle/10665/324791/9789241515559-eng.pdf, accessed 20 March 2020). 

  5. WHO child growth standards and the identification of severe acute malnutrition in infants and children. A Joint Statement by the World Health Organization and the United Nations Children’s Fund. Geneva and New York: World Health Organization and UNICEF; 2009 https://www.who.int/nutrition/publications/severemalnutrition/9789241598163_eng.pdf; accessed 20 March 2020). 

  6. BMI is calculated as weight in kg / height in m2 

  7. Short stature: < 145 cm among women of reproductive age 

  8. Cashin K, Oot L. Guide to anthropometry. A practical tool for program planners, managers, and implementers. Module 5: adults (18 years of age and older). Washington DC: USAID; 2018 https://www.fantaproject.org/sites/default/files/resources/FANTA-Anthropometry-Guide-May2018.pdf, accessed 20 March 2030). 

  9. Tang AM, Chung M, Dong K, Terrin N, Edmonds A, Assefa N et al. Determining a global mid-upper arm circumference cutoff to assess malnutrition in pregnant women. Washington DC: USAID; 2016 (https://www.fantaproject.org/sites/default/files/resources/FANTA-MUAC-cutoffs-pregnant-women-June2016.pdf, accessed 20 March 2020).