DAKAR (Thomson Reuters Foundation) - Ghana economy's is losing more than two billion dollars a year due to the impact of child malnutrition, which has driven up healthcare costs, strained the education system and hindered the productivity of the workforce, a study said on Tuesday.

Malnutrition comes in many forms, such as poor child growth and development or vulnerability to infection among those who do not get enough food, which is known as under nutrition.

Under nutrition among children costs Ghana $2.6 billion per year - 6.4 percent of its gross domestic product (GDP) - according to a study led by the African Union and backed by U.N. aid agencies and the African Development Bank.

Stunted growth, which occurs when children miss out on vital nutrients in the womb and their first two years of life, is the biggest concern, said the Cost of Hunger in Africa (COHA) study, which has been carried out in 12 other African nations.

"The goal of eliminating stunting is key to achieving zero hunger, Sustainable Development Goal 2," said Thomas Yanga, director of the World Food Programme's (WFP) Africa office.

U.N. member states agreed last year to 17 ambitious goals - the Sustainable Development Goals (SDGs) - to tackle the world's most troubling problems ranging from hunger to climate change.

"The losses to the economy can be averted through strategic interventions which ensure adequate nutrition for mothers and young children," Yanga said in a statement.

Ghana has made progress in improving child nutrition, as stunting rates have almost halved, to 19 percent from 36 percent – in just over a decade, the 2016 Global Nutrition Report showed.

Yet the COHA study found a third of adults in Ghana suffered from stunting as children, and that child mortality linked to under nutrition has reduced Ghana's workforce by seven percent.

"In northern Ghana, 30 percent of children under five are stunted or chronically malnourished," said WFP deputy regional director for West and Central Africa, Margot van der Velden.

"This not only affects their growth but also their educational development and economic potential, and consequently the future of the country," she added in a statement.

Malnutrition is responsible for nearly all half of deaths of children under five worldwide and, along with poor diets, is the main driver of disease, the 2016 Global Nutrition Report said.

(Reporting by Kieran Guilbert, Editing by Katie Nguyen.; Please credit the Thomson Reuters Foundation, the charitable arm of Thomson Reuters, that covers humanitarian news, women's rights, trafficking, corruption and climate change. Visit news.trust.org)