While fewer children attending low-income schools in Gauteng are suffering from the long-term effects of chronic malnutrition, many more are going hungry in the short term as rising food prices and economic hardship squeeze already struggling households, new research has revealed.

Researchers from the University of Johannesburg (UJ) found that the proportion of underweight children aged five to 10 attending low-resource schools doubled from 6% to 12% between 2020 and 2022, even as rates of stunting declined.

This means the proportion of underweight children increased from one in 16 to one in eight in the study period when many households lost income and state support as Covid-19 restrictions and economic shocks took hold.

"The doubling of underweight children is a warning sign," said the study's lead author, Dr Matshidiso Sello, a senior researcher at UJ's Centre for Social Development in Africa.

"What concerned me most was the increase in underweight among children despite the slight improvement in stunting. This suggests that many children are still living in households where access to adequate nutrition remains uncertain."

She said the findings suggest that many families are struggling to provide enough nutritious food in the short term, likely because of rising food prices, unemployment and the economic pressures that intensified during and after the Covid-19 pandemic.

While the decline in stunting suggests long-term investments in child health, nutrition and school feeding programmes may be paying off, the rise in underweight children points to a more immediate problem: many families are struggling to put enough nutritious food on the table.

Stunting and underweight measure two different forms of malnutrition. "Stunting reflects long-term or chronic undernutrition that usually develops during the first 1 000 days of a child's life. Once a child is older, stunting is much harder to reverse," Sello said.

Underweight reflects more immediate changes in a child's nutritional status and can respond more quickly to changes in food availability and household circumstances, she said.

"In our study, we saw a slight decline in stunting but an increase in underweight. This suggests that although South Africa has made some progress in addressing long-term nutritional problems, many children remain vulnerable to short-term shocks such as household food insecurity, rising food prices and loss of income."

The findings are a reminder that improving child nutrition is not only about preventing stunting in early childhood but also about ensuring that school-aged children continue to have access to enough nutritious food, Sello said.

"Although our study only covers the period from 2020 to 2022, there is good reason to be concerned. Since then, South Africa has continued to experience high food prices, persistent unemployment and increasing pressure on household incomes."

She said that for families that were already struggling, these economic pressures make it even more difficult to afford healthy and nutritious food.

"While we cannot say from our data alone that child undernutrition has worsened since 2022, the broader economic environment suggests that many vulnerable households are likely facing even greater challenges today."

Sello said this underscored the need for continued monitoring and investment in programmes that protect children's nutrition during economic hardship.

Her concerns echo those raised in the United Nations' latest State of Food Security and Nutrition in the World report, released this week, which warns that Africa remains the region with the highest prevalence of undernourishment and that many households still cannot afford healthy diets despite some global improvements in food security.

Another striking finding was that boys were five times more likely to be underweight than girls and more than three times more likely to be stunted.

"Our study cannot explain exactly why this happens but it is consistent with findings from other studies conducted in South Africa and other low-and middle-income countries.

"Research suggests that boys may be biologically more vulnerable to nutritional stress and illness during childhood. Some studies also suggest that boys may have different growth patterns and nutritional requirements, making them more sensitive to poor diets and difficult living conditions."

However, more research is needed to better understand why boys appear to be at greater risk in low-income communities.

"This finding tells us that nutrition programmes should pay attention to the different needs of boys and girls rather than assuming they are affected in exactly the same way."

Nutrition is one of the foundations of early childhood development, she said, pointing out that a child who receives adequate nutrition is more likely to be healthy, attentive in class and able to learn effectively.

Poor nutrition can reduce concentration, memory and energy levels, making it more difficult for children to take part in classroom activities, keep up with lessons and perform academically. Over time, this can increase the risk of absenteeism and grade repetition.

The effects do not stop at school, she said. "Children who are healthier and better educated are more likely to complete school, access employment opportunities and become economically productive adults."

Sello noted that while the child support grant of R580 has played an important role in reducing poverty and improving children's well-being, many researchers have raised concerns that its current value is still below what families need to provide an adequate nutritious diet.

Sello believes that three policy actions would have the greatest impact. The first is to gradually increase the child support grant towards the food poverty line of R855 as this would strengthen the ability of families to purchase nutritious food.

"Second, protecting and strengthening the National School Nutrition Programme is essential because, for many children, the school meal is the most nutritious meal they receive each day."

Finally, child nutrition cannot be addressed by one department alone. Stronger collaboration between the departments of health, basic education and social development is needed to identify vulnerable children early and ensure that families receive both financial support and access to health and nutrition services, she said.

She said the lack of support for low-income families also affects caregivers, with consequences that cascade to children.

Sello noted that the researchers found very high levels of caregiver unemployment and depressive symptoms, which "remind us that children's nutrition is closely linked to the well-being of their families.

"Supporting children means supporting the families who care for them. Investments in social protection, school nutrition, health services and caregiver support should work together rather than in isolation.

"If we want children to learn, grow and reach their full potential, we must ensure they have consistent access to nutritious food throughout childhood, not only during the first few years of life."