"The Impact of Nutrition during Early Childhood on Income, Hours Worked, and Wages of Guatemalan Adults," by John Hoddinott, John A. Maluccio, Jere R. Behrman, Rafael Flores, and Reynaldo Martorell

Summary of research conducted in Guatemala by Emory University, the International Food Policy Research Institute (IFPRI), the Institute of Nutrition of Central America and Panama (INCAP), the University of Pennsylvania, and Middlebury College. This study is featured in the February 2 issue of The Lancet as part of its ongoing focus on maternal and child undernutrition.

Substantial, but indirect, evidence from previous research suggests that providing infants and very young children with healthy, nutritious food is a long-term economic investment for developing countries. This study in Guatemala is the first to show direct evidence of the effects of early childhood nutrition programs on adult economic productivity and incomes.

Findings from the study show that improving nutrition in early childhood leads to significant increases in wage rates for men, suggesting that investments in early childhood nutrition can be long-term drivers of growth and a wise economic investment.

From 1969-1977, INCAP conducted a food supplementation study in four villages in Guatemala to test the effect of improved nutrition on children's physical and mental development. Children randomly received one of two supplements fortified with micronutrients. The first, atole, contained 6.4 grams of protein and was high in energy; the second, fresco, contained no protein and was low in energy.

The program enrolled all children and infants who were under seven years of age when the program was launched in 1969. Babies born during the study period were also included. Children and infants continued to participate in the program until they were seven years old or until the study ended in 1977, whichever came first. Thus, the participating children were exposed to the supplement (either atole or fresco) at different ages and for different periods of time.

In 2002-2004, researchers returned to Guatemala to collect follow-up data and interview adults who had participated in the nutrition program as children. Nearly 2,400 individuals were involved in the original study. At the time of follow-up, they were 25-42 years old. About 78 percent of the individuals were alive and living in Guatemala; 11 percent had died; 7 percent had left the country; and 4 percent were untraceable.

During the follow-up study, researchers collected economic data, including information about income-generating activities, from approximately 1,425 Guatemalans, or 60 percent of the adults who were enrolled in the original program. The topics included: a) wage labor activities (type of work; hours, days, and months worked; and wages and fringe benefits received); b) agricultural activities (amount of land cultivated; crops grown; production levels and value; use of inputs; and hours, days, and months worked); and c) non-agricultural own-business activities (type of activity; value of goods or services provided; capital stock held; and hours, days, and months worked).

Researchers then calculated annual earned income, hours worked, and hourly wage rates for each adult. Respondents who were not engaged in economic activities or participating in the labor market were excluded from the analysis.

Boys who received the high-energy, high-protein atole in the first two years of life earned on average 46 percent higher wages as adults. Boys who received atole in their first three years earned 37 percent higher wages on average. However, those who first received the supplement after age three did not gain any economic benefits as adults.

Consumption of atole in childhood did not have an effect on women's income, probably because of gender differences in labor force participation and work activities. In Guatemala, participation in the formal labor market is significantly lower for women than for men. However, preliminary analysis suggests that schooling increased for women who had consumed atole, and that reading comprehension increased significantly for both men and women.

Past research has demonstrated that the first two years of life are the "window of opportunity" when nutrition interventions have the greatest benefits for a child's health, growth, and development. This study confirms that improving nutrition in early childhood also leads to healthier and more productive adults, bringing economic returns to both individuals and societies.

The research in Guatemala was supported by grants from the National Institutes of Health and National Science Foundation.