Climatic conditions and child height: Sex-specific vulnerability and the protective effects of sanitation and food markets in Nepal

Environmental conditions in early life are known to have causal impacts on later health outcomes, but mechanisms and potential remedies have been difficult to discern. This paper uses the Nepal Demographic and Health Surveys (DHS) of 2006 and 2011, combined with earlier NASA satellite observations of variation in vegetation density (NDVI) at each child’s location and time of birth, to identify the trimesters of gestation and infancy during which climate variation can be linked to heights attained between 12 and 59 months of age. We find significant differences by sex of the fetus: males are most affected by conditions in their second trimester of gestation, and females in their first trimester after birth. Each 100 point difference in NDVI at those times is associated with a difference in height-for-age Z-score (HAZ) of 0.088 for boys and 0.054 for girls, an effect size that is similar to moving within the distribution of household wealth by one quintile for boys, and one decile for girls. The entire seasonal change in NDVI from peak to trough is on the order of 200-300 points, implying a seasonal effect on HAZ similar to 1-3 quintiles of household wealth. This effect is observed only in households without toilets; with toilets there is no seasonal fluctuation, implying protection against climatic changes in disease transmission. We also use data from the Nepal Living Standards Surveys on district-level agricultural production and marketing, and find a vegetation effect on child growth only in districts where households’ food consumption comes primarily from own production. Robustness tests find no evidence of selection effects, and placebo regressions reveal no significant artefactual correlations. Our findings regarding timing and sex-specificity are consistent with previous results, and the protective effect of sanitation and markets is a novel indication of the mechanisms by which households can gain resilience against adverse climatic conditions

Household food production is positively associated with dietary diversity and intake of nutrient-dense foods for older preschool children in poorer families: Results from a nationally-representative survey in Nepal.

Nutrition-sensitive interventions supporting enhanced household food production have potential to improve child dietary quality. However, heterogeneity in market access may cause systematic differences in program effectiveness depending on household wealth and child age. Identifying these effect modifiers can help development agencies specify and target their interventions.This study investigates mediating effects of household wealth and child age on links between farm production and child diets, as measured by production and intake of nutrient-dense food groups.Two rounds (2013 and 2014) of nationally representative survey data (n = 5,978 observations) were used to measure production and children's dietary intake, as well as a household wealth index and control variables, including breastfeeding. Novel steps used include measuring production diversity in terms of both species grown and food groups grown, as well as testing for mediating effects of family wealth and age of child.We find significant associations between child dietary diversity and agricultural diversity in terms of diversity of food groups and of species grown, especially for older children in poorer households, and particularly for fruits and vegetables, dairy and eggs. With each additional food group produced, log-odds of meeting minimum dietary diversity score (≥4) increase by 0.25 (p = 0.01) for children aged 24-59 months. For younger children aged 18-23 months there is a similar effect size but only in the poorest two quintiles of household wealth, and for infants 6-18 months we find no correlation between production and intake in most models.Child dietary intake is associated with the composition of farm production, most evident among older preschool children and in poorer households. To improve the nutrition of infants, other interventions are needed; and for relatively wealthier households, own farm production may displace market purchases, which could attenuate the impact of household production on child diets

Diet diversity and agricultural diversity quintile produced by child's age (unbalanced panel).

<p>Diet diversity and agricultural diversity quintile produced by child's age (unbalanced panel).</p

Household meat production and consumption.

<p>Household meat production and consumption.</p

Household dairy production and consumption.

<p>Household dairy production and consumption.</p

Diet diversity and number of food groups produced by child's age.

<p>Diet diversity and number of food groups produced by child's age.</p

Dietary diversity in farm vs. non-farm households by child's age.

<p>Dietary diversity in farm vs. non-farm households by child's age.</p

Household egg production and consumption.

<p>Household egg production and consumption.</p

Household legumes production and consumption.

<p>Household legumes production and consumption.</p