They said the study, published in the Lancet medical journal, made a case for country donors, aid agencies and developing nations to target feeding at the very young."Our study is the first to find a direct link between nutrition in childhood and economic productivity in later life," researcher John Hoddinott from the Washington, DC-based International Food Policy Research Institute (IFPRI) told reporters in a telephone briefing.
"The implications are stark. Governments... that are interested in welfare and poverty reduction should increase their spending on preschool nutrition."
Researchers looked at almost 1 500 people in four Guatemalan villages who had been enrolled in a nutrition study between 1969 and 1977, with two villages receiving a protein, calorie and nutrient rich porridge-like drink and two receiving a less nutritious placebo.
46% higher earnings
They found men who had received the nutritious porridge before the age of three earned 46 percent more per hour than those who did not. But there was no increase in earnings for women or for men who received the supplement only after they had passed three years of age.
The researchers said they took into account other factors such as village location and school quality.
"The ages of zero to two and zero to three are often described by nutritionists as a golden window," Hoddinott said. "In very young children, malnutrition has several malign effects. They have slower physical growth so end up being shorter. Malnutrition also affects brain development."
Being taller and stronger might help boost earnings in trades such as agricultural labouring, he said, although the researchers suspected it was the difference in cognitive - or thinking - ability that was most crucial.
The researchers said they were uncertain why women did not reap the economic benefits of better early childhood feeding, but suggested it could be due to differences in work activities. Most women in the area worked in low productivity activities such as agricultural processing so might have lacked the ability to substantially increase their wages.
Many aid agencies and developing countries target the very young with nutritional supplements but other interventions - such as United Nations World Food Programme school feeding programmes - target older children.
"If what you are looking for is to improve school attendance and improve attention then school feeding programmes are still effective," Hoddinott said.
But given limited resources he said he would rather spend money on feeding before children reached school age. – (Reuters Health)