From VOA Learning English, this is the Economics Report.

A recent study questions whether placing attention on economic growth is the best way to improve child nutrition in low- and middle-income countries.

Subu Subramanian is a professor at the Harvard School of Public Health in Massachusetts. He says there is a common belief on the best way to improve child health in developing countries. He puts it this way: "Let's just go after economic growth and then everything else will just follow."

But he says that is not always true. Take India for example, a common measure of a country's economic heath is gross domestic product (GDP). India's GDP has been growing by more than five percent a year, that is a higher growth rate than most Western countries.

Yet more than two-fifths of India's children are underweight. And Subu Subramanian says, the percentage of underweight children has changed little since the the early 1990s. He and other researchers asked a question, "was economic growth failing to reach children in countries other than India?"

They looked at health surveys carried out since 1990 in 36 low- and middle-income countries, mostly South of Africa's Sahara Desert. The researchers compared the effect of GDP growth and signs of child malnutrition - like stunted growth and being underweight. But the researchers found only a small relationship or correlation.

"practically zero to very, very small," said Subramanian.

The group reported their findings in the journal Lancet Global Health. Subu Subramanian says money should be spent on clear water and waste-treatment system, childhood immunization campaigns and other programs.

"Without these directing investments, what we are seeing is [that] economic growth by itself is not making much impact," said Subramanian.

But that is not how Lawrence Haddad sees the issue. He is head of the Institute of Development Studies in Britain. Lawrence Haddad says malnutrition has dropped sharply over the past 20 years in countries like Vietnam, Ghana or Brazil. He says economic growth was responsible for half of those declines.

"The other half is attributable to strategic investments in water, sanitation, health systems, nutrition programs," said Haddad.

He says it takes both GDP growth and the right investments to improve child nutrition.