A Lancet article reporting on children’s height and weight changes over the past 30 years makes for grim reading when it comes to South Africa. Two of the country’s top child nutrition experts unpack what this landmark study means and what we can do to improve the situation.
“Tall as trees” sounds very cliché, but it may not apply to children in many sub-Saharan African countries, according to a Lancet article reporting on children’s height and weight changes over the past 30 years.
The Lancet article pooled data from more than 2 000 studies from 200 countries with a study population of 65 million participants and reported on the projected changes of height and body mass index of school-aged children and adolescents from 1985 to 2019.
The data showed that the unhealthiest changes – gaining too little height and/or too much weight for their height occurred in many countries in sub-Saharan Africa, New Zealand and the US (all for both boys and girls), in Malaysia and some Pacific island nations (for boys) and in Mexico (for girls).
Growth measured in height and weight has long been recognised as a measure of the health of individuals, hence part of the reasoning for the promotion of routine growth monitoring for children under five years of age. In South Africa, every child is presented with a Road to Health booklet to record and monitor their weight and height measures from birth. Mothers and caregivers are encouraged to visit their health facility for monthly growth monitoring to track their child’s growth and development as a proxy for health.
A major public health concern
Malnutrition identified in the failure to grow in height and weight is a major public health concern worldwide. In South Africa, 27% of children younger than five are too short for their age, and in the same age group 15% are too fat. These indicators serve as proxies for the state of overall health. As reflected in the Lancet article, young South African children are too short and too fat.
Our adolescent nutrition profile does not paint a much better picture, with 6.1% males and 16.7% females in the age group 15 to 19 being overweight and their average height below the global average of 1.62m.
The Lancet reported that 19-year-old boys in 11 countries throughout Asia, Latin America and sub-Saharan Africa had the same mean height as that of Dutch boys aged 13.
In many countries in sub-Saharan Africa, with emerging economies, the height of children and adolescents, especially boys, has on average stagnated or become shorter since 1985. This points directly to the increasing levels of poverty driving the vicious cycle of malnutrition as households and communities struggle to access adequate and sufficiently nutritious food.
The Lancet reported that the largest improvements in the average height of children over the 35-year period were seen in emerging economies such as China, South Korea and some parts of south east Asia. For example, 19-year-old boys in China in 2019 were 8cm taller than in 1985, with their global rank changing from 150th tallest in 1985 to 65th in 2019. Over the same period, the average height of South African girls stagnated, while boys gained only about 2cm. Nineteen-year-old South African girls had the same average height as 12-year-old Dutch girls, while South African boys of the same age had the average height of 14-year-old Dutch boys.
South Africa is mentioned in the report as one of the countries where children compared fairly well with international growth references at the age of five, but by the time they reached 19 years they fell behind due to insufficient growth in height during school-age years.
While little or no height was gained per year of age, girls in particular gained weight, so the average weight of South African girls in each age group was markedly higher after 2010 than in the 1980s and was in the overweight range at age 19.
The Lancet report also highlighted that while children in some countries grow healthily to age five, they fall behind in their school years in terms of growth in length. This highlights that there is an imbalance between investment in improving nutrition in preschoolers, and in school-aged children and adolescents.
This issue was especially important during the Covid-19 coronavirus pandemic, when schools were closed throughout the world and many poor families unable to provide adequate nutrition for their children.
This recognition that school feeding is an important and integral intervention to promote and sustain child nutrition prompted civil society in South Africa to approach the courts to force government to reinstate the national school nutrition programme.
While many school-aged children do not have access to adequate nutritious food for linear growth and physical development, they seem to have high enough intakes of sweetened cold drinks and cheap snack foods to gain excessive weight. Some of these cold drinks and snacks are even available in the school environment at low cost. This is probably an important driver of the weight gain reported in South African school-age girls.
Ensure food security
The Lancet report reaffirms the imperative to sustain adequate food and nutrition support throughout the critical stages of life, including during pregnancy, early childhood, adolescent and adult years to consolidate and reap the benefits gained in food and nutrition interventions and investments in infants and children younger than five.
This is imperative because adolescents and women of childbearing age are the future parents of the next generation of children. Mothers with poor nutritional status will bear children with poor nutritional status and this is a lost and costly opportunity as malnutrition casts a long shadow into the future, robbing individuals, communities and countries of health, wellbeing and development.
If we are to improve child health and nutrition, governments need to ensure food security. Food security is defined as all people at all times having physical and economic access to adequate amounts of nutritious, safe and culturally appropriate foods. This will help children grow taller without gaining excessive weight for their height.
To achieve these goals, South Africa needs policies to support an enabling environment, with restricted access to unhealthy foods and drinks and more access to facilities in the community and in the school environment for safe play and sports.
Dr Witten is based at the University of the Free State’s faculty of health sciences, division of health science education
Kruger is a professor at the North-West University’s Centre of Excellence for Nutrition
This article was produced for Spotlight – health journalism in the public interest