Child growth is an indicator of health and nutritional status over the short and long term. Growth stunting is one important indicator of malnutrition. Immediate causes of malnutrition include inadequate dietary intake and illness commonly due to poverty. In the early years, malnutrition has a significant impact on children’s physical and mental development. It is dependent on a number of factors but primarily on the age of exposure and duration. Those affected earlier and for longer periods are likely to have compromised neurological development and have the poorest outcomes – particularly in cognitive development.

Malnutrition in South Africa is a significant problem. In 2016, the South African Demographic and Health Survey reported the following rates for children under 5 years of age:

  • Stunting = 27%
  • Underweight = 6%
  • Overweight = 13% (Hall et, al., 2019).

Many children attending early learning programmes are poor and at risk for undernutrition.  When children are assessed on the ELOM it is common practice to measure their growth status as well. This takes the form of measuring their Height and deriving a Height for Age Z (HFAZ) score. This then enables us to see the relationship between the child’s growth status and their ELOM performance. Research conducted thus far by the ELOM team at Innovation Edge, has found a clear association between children’s growth status and their ELOM scores. For example, children with higher height-for-age scores (healthier and less likely to be malnourished) performed significantly better on all ELOM domains and on the ELOM Total score in the Early Learning Programme Outcomes study (Dawes et. al., 2020).

Knowing children’s growth status provides an opportunity for intervention. Recent longitudinal research shows that a proportion of children recover from early growth stunting. Potential for recovery is dependent on the children’s circumstances and the extent and timing of early-life stunting. For example, 44% of Indian children in the Young Lives longitudinal study whose growth was stunted as infants had normal growth by age 5. But of those infants whose growth was severely stunted, only 20% were no longer stunted at this age (Georgiadis & Penny, 2017; Boyden, Dawes, Dornan & Tredoux 2019). Also, those whose growth status recovered to normal by middle childhood, did better on cognitive tests than those children did not recover, but not as well as those who were never stunted. Those with prolonged and early stunting, perform worst.

These changes are not yet well understood but it is clear that interventions to improve health and nutrition are critical in both the prevention of stunting and its mitigation. Therefore, if early childhood programmes measure children’s growth status themselves (or receive assistance from health services to do so), they can know the extent of the problem in their children. They can also examine the effect of growth deficits on development by using the ELOM to measure their functioning.

By knowing their children’s growth status, ECD programmes can play an essential part in addressing this widespread source of both short and long-term developmental deficit by referring children for the necessary nutritional and health support.

Growth measurement in ELOM studies

Growth stunting is the most common form of malnutrition in South Africa. It is chronic (long-term) condition and a reflection of the overall health status of the child. Stunting is caused by poor nutrition and also repeated infections over extended periods.

The growth indicator used in ELOM studies is Height for Age Z Score (HFAZ) which permits us to detect whether a child’s height is normal for their age or too low (stunted). The child’s height is measured, a standardised HFAZ score is derived and compared to the norms (expected score) for children of the same age and sex developed by the World Health Organisation (WHO). South African Road to Health Booklets provide Growth Charts for children under 5 years.

Stunting (low height-for-age)

Definition Stunting: Children whose HFAZ < –2 SD (standard deviations) of the WHO Child Growth Standards median.

Definition Severe Stunting: Children whose HFAZ < –3 SD of the WHO Child Growth Standards median.

Children’s height should be measured with a stadiometer. If not available, a tape measure fixed from floor level can be used. Further practical details can be found here with links to the WHO websites that provide information on assessing children’s growth status and determining whether or not development is compromised.

To compute the relationship between ELOM scores and HFAZ, a sample of not less than 25 children in the ELOM age range (50-69 months) with totally sound data is required. However, it is nearly always the case that the records of some children contain errors and cannot be used. A minimum of sample 35 children in the ELOM age range is therefore strongly advised.

Other indicators of malnutrition

In this section we provide a list of other commonly used measures in child health and nutrition surveys. These have not been measured in ELOM studies to date.

Underweight (low weight-for-age)

As noted above, underweight is far less prevalent in South Africa and is an indicator of both acute and chronic malnutrition. The standard measure of underweight is Weight for Age. To measure children’s Weight for Age, their age and weight are recorded. A standardised Weight for Age Z score (WFAZ) is derived and compared to the norms (expected score) for children of the same age and sex developed by the WHO.

Definition Underweight: Children whose WFAZ < –2 standard deviations (SD) of the WHO Child Growth Standards median

Wasting (low weight-for-height)

Wasting is an indicator of acute malnutrition. There are two approaches to measurement.

  1. Children’s age, height and weight are recorded to derive a Weight for Height Z score (WFHZ). Wasting definition using Weight for Height: WFHZ < –2 SD of the WHO Child Growth Standards median.
  1. Mid Upper Arm Circumference (MUAC) tapes are also used to measure wasting in children aged 6 – 59 months. Wasting definition using MUAC: An upper arm circumference <11.0 cm indicates severe acute malnutrition.


Overweight in children is on the increase (13% <5 years in South Africa), particularly in children living in low income settings. Children’s age, height and weight are recorded.

Definition Overweight: WFHZ > +2 SD of the WHO Child Growth Standards median.

Definition Obese: Children <60 months with a body mass index (BMI) =>30kg/m2. BMI= child’s weight in kg / child height in metres.


  • A very useful and comprehensive guide to measuring children’s growth.
  • The World Health Organisation provides child growth standards and instruments for their calculation.
  • Mean Upper Arm Circumference: for norms see the World Health Organisation Arm circumference-for-age site.


Benny, L., Penny, M. and Boyden, J. (2018) Early is best but it’s not always too late: Young Lives evidence on nutrition and growth in Ethiopia, India, Peru and Vietnam, Oxford: Young Lives.

Boyden, J., Dawes, A., Dornan, P. & Tredoux, C. (2019). Tracing the Consequences of Child Poverty: Evidence from the Young Lives study in Ethiopia, India, Peru and Vietnam. Bristol: University of Bristol Policy Press.

Dawes, A., Biersteker, L., Girdwood, E., Snelling, M. and Horler, J. (2020). Early Learning Programme Outcomes Study Technical Report. Claremont Cape Town: Innovation Edge and Ilifa Labantwana.

Georgiadis, A. and Penny, M. (2017) ‘Child undernutrition: Opportunities beyond the first 1000 days’, The Lancet Public Health, 2(9), 399.

Hall K, Sambu W, Almeleh C, Mabaso K, Giese S & Proudlock P (2019) South African Early Childhood Review 2019. Cape Town: Children’s Institute, University of Cape Town and Ilifa Labantwana.

Hendricks, M., Goeiman H. & Hawkridge, A. (2013). Promoting healthy growth: Strengthening nutritional support for mothers, infants and children. In Jameson, L., Berry, L. and Lake, L. (Eds.), South African Child Gauge 2013 (pp. 44-49). Cape Town: Children’s Institute, University of Cape Town.

Saloojee, H. (2007). Monitoring child health. In Dawes, A. Bray, R. & van der Merwe, A. (Eds.), Monitoring child wellbeing. A South African rights-based approach (pp. 93-109). Cape Town. HSRC Press.

Sanders, D. & Reynolds, L (2017). Ending stunting: transforming the health system so children can thrive. In Jameson, L., Berry, L. and Lake, L. (Eds.), South African Child Gauge 2017 (pp. 68-76).  Cape Town: Children’s Institute, University of Cape Town.

World Health Organisation (2010) Nutrition Landscape Information System (NLIS) Country Profile Indicators Interpretation Guide. Geneva: World Health Organisation.