Paul Melgar

Adult consequences of growth failure in early childhood

Background: Growth failure is associated with adverse consequences, but studies need to control adequately for confounding. Objective: We related height-for-age z scores (HAZs) and stunting at age 24 mo to adult human capital, marriage, fertility, health, and economic outcomes. Design: In 2002–2004, we collected data from 1338 Guatemalan adults (aged 25–42 y) who were studied as children in 1969–1977. We used instrumental variable regression to correct for estimation bias and adjusted for potentially confounding factors. Results: A 1-SD increase in HAZ was associated with more schooling (0.78 grades) and higher test scores for reading and nonverbal cognitive skills (0.28 and 0.25 SDs, respectively), characteristics of marriage partners (1.39 y older, 1.02 grade more schooling, and 1.01 cm taller) and, for women, a higher age at first birth (0.77 y) and fewer number of pregnancies and children (0.63 and 0.43, respectively). A 1-SD increase in HAZ was associated with increased household per capita expenditure (21%) and a lower probability of living in poverty (10 percentage points). Conversely, being stunted at 2 y was associated with less schooling, a lower test performance, a lower household per capita expenditure, and an increased probability of living in poverty. For women, stunting was associated with a lower age at first birth and higher number of pregnancies and children. There was little relation between either HAZ or stunting and adult health. Conclusion: Growth failure in early life has profound adverse consequences over the life course on human, social, and economic capital.

Effect of Zinc on Efficacy of Iron Supplementation in Improving Iron and Zinc Status in Women

Iron and zinc may interact in micronutrient supplements and thereby decrease efficacy. We investigated interactive effects of combined zinc and iron supplementation in a randomized controlled trial conducted in 459 Guatemalan women. Four groups were supplemented for 12 weeks: (1) weekly iron and folic acid (IFA); (2) weekly IFA and 30 mg zinc; (3) daily IFA; (4) daily IFA and 15 mg zinc. Effects were assessed by generalized linear regression. Baseline hemoglobin (Hb) concentration was 137.4 ± 15.5 g/L, 13% were anemic and 54% had zinc deficiency. Hb cconcentrations were similar by supplement type, but Hb concentrations improved significantly in anemic women at baseline (increase of 21.8 g/L). Mean percentage changes in serum ferritin were significantly higher in daily compared to weekly supplemented groups (86% versus 32%). The addition of zinc to IFA supplements had no significant impact on iron or zinc status. In conclusion, adding zinc to IFA supplements did not modify efficacy on iron status or improve zinc status, but daily supplementation was more efficacious than weekly in improving iron stores.

The Nutrition Intervention Improved Adult Human Capital and Economic Productivity

This article reviews key findings about the long-term impact of a nutrition intervention carried out by the Institute of Nutrition of Central America and Panama from 1969 to 1977. Results from follow-up studies in 1988-89 and 2002-04 show substantial impact on adult human capital and economic productivity. The 1988-89 study showed that adult body size and work capacity increased for those provided improved nutrition through age 3 y, whereas the 2002-04 follow-up showed that schooling was increased for women and reading comprehension and intelligence increased in both men and women. Participants were 26-42 y of age at the time of the 2002-04 follow-up, facilitating the assessment of economic productivity. Wages of men increased by 46% in those provided with improved nutrition through age 2 y. Findings for cardiovascular disease risk factors were heterogeneous; however, they suggest that improved nutrition in early life is unlikely to increase cardiovascular disease risk later in life and may indeed lower risk. In conclusion, the substantial improvement in adult human capital and economic productivity resulting from the nutrition intervention provides a powerful argument for promoting improvements in nutrition in pregnant women and young children.

Cohort Profile: The Institute of Nutrition of Central America and Panama (INCAP) Nutrition Trial Cohort Study

In the mid-1960s, protein deficiency was seen as themost important nutritional problem facing the poor inthe developing countries, and there was considerableconcernthatthisdeficiencyaffectedchildren’sabilitytolearn. The Institute of Nutrition of Central America andPanama (INCAP), based in Guatemala, became thelocusofaseriesofstudiesonthissubject,thatinformedthe development of a large-scale randomized nutri-tional intervention trial that ran from 1969 to 1977.

Social and Economic Development and Change in four Guatemalan Villages: Demographics, Schooling, Occupation, and Assets

This article uses census data and village histories to examine changes over the last 35 years in the four villages where the Institute of Nutrition of Central America and Panama (INCAP) Longitudinal Study (1969–77) was conducted and offers a rare picture of development and change in rural localities over a long period of time. In addition, by characterizing the environment in which the subjects of this study were raised, we provide context for and inputs into quantitative analyses of data collected at various points in time on these subjects. The villages have undergone massive demographic, social, and economic change. Initial differences have conditioned many of these changes, especially differences associated with agricultural potential and location. Originally these villages were rather isolated, but road and transportation access has improved substantially. The populations in the villages have more than doubled and also have aged. While marriage patterns have held steady, religious practice has changed a great deal. After many years of steady out-migration, three of the four villages are more recently experiencing net in-migration, a pattern associated with ease of access. Schooling access and outcomes also have improved, with average grades of schooling nearly tripling and literacy doubling to levels currently above national averages. Although agriculture remains an important component of individual livelihood strategies, non-agricultural sources of employment have become more important. Much of this change is associated with declining agricultural markets and increased access to non-agricultural jobs near the villages and in the capital. Accompanying these changes has been an improvement in living standards as measured by a number of indicators of household living conditions and consumer durable goods.

INCAP Oriente Longitudinal Study: 40 Years of History and Legacy

Our purpose in this article is to describe the objectives, design, overall coverage, and main domains of data collection of the Institute of Nutrition of Central America and Panama Oriente Longitudinal Study and subsequent follow-up studies. This supplementary feeding trial targeted to pregnant and lactating women and children from birth to 7 y of age, conducted in 4 rural Guatemalan villages (1969-77) with a series of follow-up studies (1988-2007), is one of the richest sources of information on the effects of nutrition, growth, development, and human capital in the developing world, with outstanding data from gestation to adult age and 40 y of follow-up. Its results have influenced nutrition knowledge and policy with over 300 scientific publications. We present brief descriptions of preliminary studies that were critical for the success of the trial and the design and methods used during the trial and in the follow-up studies, in chronological order.

Physical fitness, body composition, blood pressure, and blood metabolic profile among young Guatemalan adults.

We assessed the distribution of several risk factors related to health: muscular strength (handgrip strength), cardiovascular endurance (step test), flexibility (sit and reach test), anthropometry and body composition, blood pressure, fasting plasma glucose, lipid profile, and hemoglobin in a cohort of Guatemalan adults who were born in four rural villages between 1962 and 1977. By 2002 approximately 32% had migrated to Guatemala City or elsewhere in the country. Men are more physically fit and leaner than women. Fatness, poor physical fitness, and metabolic syndrome are highly prevalent in women living in both rural and urban areas. Risk profiles worsen with increasing age. Men who migrated to Guatemala City have lower physical fitness, greater fatness and systolic blood pressure, and worse lipid profile than men who still live in their original villages. Such a pattern was not evident in women, except that blood pressure was higher in urban women than in women who lived in their original villages.