Food and Nutrition Bulletin

Children's participation and supplement intake patterns in an eight-year, community-based intervention trial in Guatemala are presented. The supplements were either high-energy, high-protein atole or low-energy, no-protein fresco.

Participation rates were between 65% and 85%, with few differences by village (N = 4) or child age (0–7 years). The percentage of days of attendance at the supplementation centre and the volume of supplement consumed, however, were significantly higher in villages that were given atole for children under flour years old. After the age of four, children who received fresco consumed more volume. Supplement energy was significantly greater for children receiving atole at all ages. Proximity to the supplementation centre and larger family size were significant predictors of attendance for both supplements. Low socio-economic status was highly associated with increased attendance for children consuming atole, but not fresco.

Analyses using these data should consider the possible biases introduced by differential self-selection between supplement types, particularly those that were potentially confounded by attendance or socioeconomic status.

Village-level infant mortality rates (IMRs) before, during, and after a food supplement and health care intervention in four villages in eastern Guatemala 1969–1977 and in three control villages are compared. Data on all pregnancies and outcomes for 988 women were obtained by means of a retrospective women's life history survey. After controlling for baseline values, the average IMR in two villages receiving supplementation with a protein-and energy-rich drink and health care was 60 per 1,000 live births, compared with an average rate of 113 in the control villages (p<.05). The rate in two villages receiving the same type of health care but a low-energy supplement was 91 per 1,000 and not significantly different from that in the control villages. The decline in the IMR in these villages points strongly to the programme's impact, but the relative importance of food supplements and health care is ambiguous.

Secular trends in the stature and head circumference of adults born between 1905 and 1959 and in the length of three-year-old children born between 1965 and 1985 from four villages of eastern Guatemala are analysed. Data were collected before (1968), during (1969–1977), and after (1988) a longitudinal protein-energy supplementation trial conducted in the four villages. No secular trends are observed in the age-adjusted height or the head circumference of the adults studied; similar results are obtained whether a longitudinal or a cross-sectional method is used to correct height for the effects of ageing. A positive and significant linear trend is observed in the length of the three-year-olds. The estimated increase of 2.5–3.3 cm seen over this 20-year period represents only approximately 27% of the total deficit in length seen in these children in 1968 (11 cm).

This paper puts the four INCAP longitudinal study villages in their economic and social setting. Beginning with a short historical account of the formation of Ladino peasantries in Guatemala, it then recounts the particular history of each of the villages, describes their basic ecological features, and gives a more detailed description of the systems of production now found in each village. Differences related to the income-earning strategies available, to the allocation of household labour, and to the participation of women in income-earning activities are particularly examined. Differences are also noted in the infrastructures of the communities and their demographic features. All these differences may have important effects, either individually or interactively, on the nutrition of individuals. Additional research is needed to assess the magnitude of these effects on the nutrition status of the study participants.

This is an overview of ten papers published in this issue of the Food and Nutrition Bulletin dealing with two components of a nutrition intervention study: the INCAP longitudinal study, 1969–1977, and the follow-up study, 1988–1989. The latter is a continuation of the former and seeks to test the hypothesis that nutritional improvements in early childhood lead to improved human capital formation in adolescents and young adults. Beneficial outcomes have been found to include greater body size and fat-free mass (particularly in females), improved working capacity in males, and enhanced intellectual performance in bath sexes.

In the mid-1960s a longitudinal, multidisciplinary nutrition intervention study was undertaken in rural Guatemala by the Institute of Nutrition of Central America and Panama in conjunction with the US National Institute of Child Health and Human Development. The goal was to elucidate the relationship between undernutrition in pregnancy and early childhood, health, and subsequent behavioural development in infants and young children. Extensive detailed planning coupled with three years of pilot studies in the field preceded the initiation of the longitudinal study in 1969. This article outlines the problems encountered in planning and implementing the study, and their resolution. Many of these experiences will be helpful to others considering community-based intervention studies.

The Institute of Nutrition of Central America and Panama (INCAP) carried out a longitudinal study of the effects of nutritional improvements on growth and development in early childhood in four villages in eastern Guatemala, 1969–1977, with a preparatory survey in 1967 and a follow-up study of the participants in 19881989. This paper examines differences among the four villages in education, occupation, quality of housing, and demographic profiles over a 20-year period, focusing on comparisons between the two villages that received a high-energy, high-protein supplement and the two that received a low-energy supplement at two different times: before the initial longitudinal study and before the follow-up study. The results suggest gradual improvement in all the villages on a number of indicators. However, the two pairs of village were not comparable on all measures; of particular concern for the interpretation of effects on cognitive development are differences in education.

The 1988–1989 INCAP follow-up study on the effects of early nutrition supplementation in child growth and development was the first long-term, comprehensive follow-up of a nutrition intervention. The subjects were former participants in the longitudinal study of 1969–1977, who were 10–26 years old at the time of measurement. The hypothesis of the follow-up study was that improved nutrition in early childhood leads to enhanced human capital formation. Cross-sectional data were collected on physical growth and body composition, maturation, work capacity, intellectual performance, and school achievement.

The INCAP longitudinal study (1969–1977) was designed to test the hypothesis that nutrition supplementation improves the cognitive test performance of infant and preschool children. The hypothesis was based on a series of arguments about effects of supplementation on brain development that have not been supported by subsequent research. Both early reports of these studies and current re-examination of the data suggest effects during the preschool years, but of modest magnitude.

The INCAP longitudinal study (1969–1977) was carried out in four Guatemalan villages to assess the effects of intra-uterine and preschool malnutrition on growth and mental development. To achieve this, food supplements were provided to pregnant women and young children. Two villages were given a high-protein, high-energy drink and two a no-protein, low-energy drink. Both supplements contained vitamins and minerals. The key features of the final study design implemented in 1969 are noted, together with its strengths and weaknesses. The selection of the study villages is described in detail, and the nature of the randomized nutritional intervention and that of the medical care programme offered to all the villages are presented. The methods of data collection and quality-control procedures are also detailed. The information should be of interest to those wishing to use and understand the INCAP/Cornell data set.

This paper describes the data collection of a follow-up study of subjects who received nutrition supplementation during their early childhood. At the time of follow-up, the subjects were between 10 and 26 years old. The study subjects; the tests, measurements, and interviews made on them; the organization and logistics of the data collection; the training, supervision, and data flow processes; and the teams responsible for the data collection are all described briefly. Coverage rates are shown by village, study area, migration status, sex, and age cohort. Potential biases due to incomplete coverage are discussed.