Around three in 10 young children in Swaziland are stunted by hunger, and 270,000 workers are also physically affected, an official said Tuesday, citing a government-backed study.

The report, by the Swazi government supported by the World Food Programme, found that around 3.1 percent of GDP was lost annually due to the long-term fall out.

The figure is equal to $92 million (69.4 million euros).

"The real costs are in health and education, children perform poorly at school, even their intelligence quota becomes low and they work below their capacity which affects national productivity levels," said Lonkhululeko Magagula, chief economist in the ministry of planning.

According to the Cost of Hunger in Africa (COHA) study, eight percent of child deaths are linked to undernutrition.

Magagula said 12 percent of school years being repeated in Swaziland, Africa's last absolute monarchy, are associated with stunting.

When it comes to adults, some 270,000 -- roughly 40 percent of workers -- are physically affected due to chronic malnutrition in early childhood.

According to the report, based on 2009 data, an estimated 37 million working hours were lost due to nutrition-related deaths.

Child mortality associated with undernutrition has reduced Swaziland workforce by 0.7 percent.

The study further says that 69 percent of all child under-nutrition go untreated.

While nearly 46,000 of 156,000 children aged under five were affected by stunting, this rose to nearly two out of every five children aged between 12 and 24 months old.

"Our next step as a government is how we address hunger. We must attend pregnant mothers in malnutrition," Magagula told AFP.

According to the World Food Programme, 40 percent of Swazis survive on less than $1.25 per day.