Contribution of Food from Market Purchases and Home Production to Child Nutrient Intake: Evidence from the EFFECTS Study Baseline Data

BACKGROUND

Child undernutrition is prevalent in Tanzania, and households rely primarily on local markets and home production as food sources. However, little is known about the contribution of food market purchases to nutrient intakes among children consuming complementary foods.

OBJECTIVES

To quantify the relationships between diversity of foods purchased and produced by households and adequate child nutrient intake in Mara, Tanzania.

METHODS

Cross-sectional baseline dietary and household food source data from the Engaging Fathers for Effective Child Nutrition and Development in Tanzania study were collected from mothers of 586 children aged 9-23 mo clustered in 80 villages in Mara, Tanzania. We conducted mixed effects linear regressions to quantify the association between the diversity of foods consumed at home, from market purchases and home production, and nutrient intake adequacy (based on 24-h food recalls).

RESULTS

Children had inadequate diets, with fewer than half of children consuming adequate amounts of vitamin A, vitamin B1 (thiamine), vitamin B2 (riboflavin), vitamin B9 (folate), calcium, iron, and zinc. Breastfeeding was associated with higher overall mean adequacy (b = 0.15-0.19 across models, P < 0.001). Diversity of foods purchased was positively associated with the intake of vitamin B12 and calcium (both P < 0.001); this effect was attenuated among breastfed children. Among nonbreastfed children, production diversity was positively associated with vitamin A intake (b=0.04; P < .05) but not with intake of other nutrients.

CONCLUSIONS

Both household food purchase and food production diversities were positively associated with children's nutrient intake in rural Mara, Tanzania. Nutrition programming should consider the role of food markets in addition to home food production to improve child diets. This trial was registered at clinicaltrials.gov as NCT03759821, https://clinicaltrials.gov/study/NCT03759821.

Effective nutrition governance is correlated with better nutrition outcomes in Nepal

BACKGROUND

The public health burden of undernutrition remains heavy and widespread, especially in low-income countries like Nepal. While predictors of undernutrition are well documented, few studies have examined the effects of political will and quality of policy or program implementation on child growth.

METHODS

Data were collected from two nationwide studies in Nepal to determine the relationship between a metric of nutrition 'governance' (the Nutrition Governance Index), derived from interviews with 520 government and non-government officials responsible for policy implementation and anthropometry measured for 6815 children in 5556 households. We employed Generalized Estimating Equation (GEE) and multilevel regression models.

RESULTS

A higher NGI (more effective nutrition governance) is positively associated with height-for-age as well as weight-for-height in children over 2 years of age compared to younger children (HAZ; β = 0.02, p < 0.004, WHZ; β = 0.01, p < 0.37). Results from the hierarchical model show that a one-point increase in the NGI is significantly associated with a 12% increase in HAZ and a 4% increase in WHZ in older children (> 24 months old). Mothers' education, child's age, BMI and no fever in the past 30 days were also protective of stunting and wasting. Seven percent and 17% of the overall variance in HAZ and WHZ, respectively, are accounted for by variations across the 21 district locations in which sampled households were located. Mean HAZ differs considerably across districts (intercept = 0.116, p < 0.001).

CONCLUSIONS

These results highlight the importance of effective management of policy-based programming and resource use to bring about nutrition gains on the ground. The NGI explained a non-negligible amount of variation in HAZ and WHZ, which underscores the fundamental role that good governance plays in promoting child nutrition and growth, and the value of seeking to measure it to assist governments in moving policies from paper to practice.

Dietary Diversity in Nepal: A Latent Class Approach

BACKGROUND

Nutritional status has important implications for labor productivity, lifetime earnings, and country-wide economic development. Dietary diversity is an important contributor to nutrition.

OBJECTIVE

To identify how patterns of food consumption are related to dietary diversity and to measure the potential for policy interventions to influence diet complexity.

METHODS

Household dietary diversity scores were constructed using data from 11 809 rural and urban households surveyed in Nepal between 2013 and 2016. Diversity scores were based on 7-day recall information on food purchases and food consumed directly from agricultural production. Reported consumption from 14 food groups was mapped into 4 distinct dietary patterns via latent class analysis. Ordered probit regressions were used to identify factors associated with observed diet patterns.

RESULTS

Diets are heterogeneous and map into 4 clusters along a continuum of complexity. Three identified diets are vegetarian and 1 is nonvegetarian. Diet complexity is associated with geography and socioeconomic features of the sample. On average, poor and agricultural households have less complex diets and households receiving remittances have more complex and higher quality diets. Road density is positively correlated with diet complexity. We find evidence of modest reductions in diet quality over the sample period.

CONCLUSIONS

Results confirm heterogeneous dietary behavior of Nepalese households. The identified patterns could be used to more effectively target policies directed at nutrition education or efforts to improve health by diversifying and improving the nutritional quality of household diets, for example, through supplemental feeding programs, home garden promotion, or targeted food assistance programs.

Aflatoxin exposure and child nutrition: measuring anthropometric and long-bone growth over time in Nepal

BACKGROUND

Naturally occurring aflatoxins may contribute to poor growth and nutritional statuses in children.

OBJECTIVES

We analyzed the relationship between contemporary and lagged aflatoxin exposure and 1) length-for-age z-score (LAZ); and 2) length, knee-heel length, stunting, weight-for-age z-score (WAZ), and weight-for-length z-score (WLZ).

METHODS

We conducted a longitudinal birth cohort study involving 1675 mother-infant dyads in rural Nepal. Participants were repeatedly visited from pregnancy to 2 years of age (2015-2019). One blood sample was collected during pregnancy and 4 samples were collected from the children at 3, 6, 12, and 18-22 months of age to measure concentrations of aflatoxin B1 (AFB1)-lysine adduct. Multivariate linear fixed-effects and logistic models with generalized estimating equations were used to identify associations between child growth and aflatoxin exposure.

RESULTS

AFB1-lysine adducts were detected in the majority of children (at 3 months, 80.5%; at 6 months, 75.3%; at 12 months, 81.1%; and at 18-22 months, 85.1%) and in 94.3% of pregnant women. Changes in contemporary ln child AFB1-lysine adduct concentrations were significantly associated with changes in LAZ (β, -0.05; 95% CI, -0.09 to -0.02; P = 0.003), length (β, -0.19; 95% CI, -0.29 to -0.10; P < 0.001), knee-heel length (β, -0.09; 95% CI, -0.13 to -0.05; P < 0.001), and WAZ (β, -0.04; 95% CI, -0.07 to -0.005; P = 0.022). Serum aflatoxin concentrations were associated with stunting (OR, 1.18; 95% CI, 1.05-1.32; P = 0.005). Similar results were found in the models using changes in contemporary ln AFB1 adjusted for changes in child weight, with significant associations with changes in WLZ (β, -0.07; 95% CI, -0.10 to -0.03; P < 0.001). Changes in time-lagged ln AFB1 (unadjusted and adjusted for changes in child weight) were associated with changes in length and knee-heel length.

CONCLUSIONS

Our results add to the growing body of evidence confirming chronic aflatoxin exposure and suggest that exposure is significantly correlated with various negative growth outcomes, which may vary by child weight status. This trial was registered at clinicaltrials.gov as NCT03312049.

Informal food environment is associated with household vegetable purchase patterns and dietary intake in the DECIDE study: Empirical evidence from food vendor mapping in peri-urban Dar es Salaam, Tanzania

We study the relationship between the food environment (FE) and the food purchase patterns, dietary intakes, and nutritional status of individuals in peri-urban Tanzania. In Africa, the prevailing high density of informal vendors creates challenges to characterizing the FE. We present a protocol and tool developed as part of the Diet, Environment, and Choices of positive living (DECIDE) study to measure characteristics of the FE. We mapped 6627 food vendors in a peri-urban settlement of Dar es Salaam, of which over 60% were semi-formal and informal (mobile) vendors. We compute and compare four FE metrics inspired by landscape ecology—density, dispersion, diversity, and dominance—to better understand how the informal food environment relates to food purchase patterns, diets, and nutritional status among households with persons living with human immunodeficiency virus (PLHIV).

•

In Tanzania, a high density of informal vendors within this transitioning food system creates challenges to characterizing the food environment.

•

We develop four metrics inspired by landscape ecology to characterize formal, semi-formal, and informal food environments.

•

We use these metrics to evaluate associations to household food purchase patterns, energy intake, and nutritional status.

•

Vegetables, especially green leafy vegetables, were primarily sold by informal mobile food vendors, most of whom were women.

•

A greater density of vegetable vendors or informal vendors within 500 meters of a household is associated with a higher likelihood of vegetable purchases and lower energy intake.

•

The role of informal and semi-formal food vendors in supporting consumption of nutritious diets should not be discounted, and gender sensitive actions to promote their livelihoods is needed.

Rainfall and child weight in Uganda

We combine data from the 2006 and 2011 Uganda Demographic and Health Surveys (UDHS) with rainfall data and two waves of the Ugandan National Household Survey (UNHS) to study patterns in child weight, as measured by weight-for-height z scores (WHZ), among 3492 rural children below age 5 in Uganda. We focus on rainfall as a nutrition driver along agriculture and disease pathways. We find a positive and significant association between crop yield and WHZ, but the magnitude of this association diminishes as we control for covariates, especially the use of productivity-enhancing agricultural inputs. We find diarrheal disease to have a negative and significant association with WHZ, and modifying effects of social and environmental factors along the disease pathway. Contemporaneous rainfall is associated with a lower likelihood of diarrheal disease in areas with excess rainfall and a higher likelihood of diarrheal disease in rainfall deficit areas. Our findings reinforce calls for targeted and situation-sensitive policies to promote child nutrition.

Dietary determinants of aflatoxin B1-lysine adduct in pregnant women consuming a rice-dominated diet in Nepal

Background

Aflatoxins are found in diverse foods widely consumed worldwide. This study investigated the association between aflatoxin exposure and (a) consumption of specific foods, (b) dietary diversity (DD), and (c) seasonality.

Methods

Women enrolled in the AflaCohort Study in Banke, Nepal (n = 1648) were asked how often they ate certain food items in the past 7 days and 24 h. Serum aflatoxin B₁-lysine (AFB₁-lys) adduct levels, measured during pregnancy, were determined using high-performance liquid chromatography. Multivariable ordinary least squares and quantile regression models were used to examine incremental increases in AFB₁-lys adduct levels per frequency of food consumption and the relationship between DD, seasonality, and increases in AFB₁-lys adduct.

Results

Roughly 94% of women were exposed to aflatoxin (geometric mean 1.37 pg/mg). Women in the 30th, 50th, and 70th quantiles of aflatoxin exposure who reported one more occasion of maize consumption in the past week showed increases in AFB₁-lys adduct levels: 0.094, 0.112, and 0.109 pg/mg (p < 0.05, all). Women in the 30th, 50th, 70th, and 90th quantiles of exposure who reported one more occasion of groundnut consumption in the past week also showed increases in AFB₁-lys adduct levels: 0.058 (p < 0.001), 0.085 (p < 0.01), 0.133 (p < 0.001), and 0.133 (p < 0.001) pg/mg. Winter month recruitment was positively associated with AFB₁-lys adduct levels at all quantiles of aflatoxin exposure (range: 0.313–1.101 pg/mg, p < 0.001). DD was not predictive of aflatoxin exposure.

Conclusions

Our findings justify integrated approaches to aflatoxin reduction, including regulatory, agricultural, and food safety interventions across the value chain and at the household level.

Relatively Low Maternal Aflatoxin Exposure Is Associated with Small-for-Gestational-Age but Not with Other Birth Outcomes in a Prospective Birth Cohort Study of Nepalese Infants

BACKGROUND

Exposure to aflatoxin has garnered increased attention as a possible contributor to adverse birth outcomes.

OBJECTIVE

The objective of this study was to investigate the relation of maternal aflatoxin exposure with adverse birth outcomes such as birth weight, birth length, anthropometric z scores, low birth weight (LBW), small-for-gestational-age (SGA), stunting, and preterm birth (PTB).

METHODS

This study used maternal and newborn data from the AflaCohort Study, an ongoing birth cohort study in Banke, Nepal (n = 1621). Data on aflatoxin B1 (AFB1)-lysine adducts in maternal serum were collected once during pregnancy (at mean ± SD: 136 ± 43 d of gestation). Maternal serum AFB1-lysine adduct concentration was measured via HPLC. Linear and logistic regression analyses were used to determine if maternal aflatoxin exposure was associated with 1) birth weight and length (primary outcomes) and 2) anthropometric z scores, LBW (weight <2.5 kg), SGA (weight <10th percentile for gestational age and sex), stunting at birth (length-for-age z score less than -2), or PTB (born <37 weeks of gestation) (secondary outcomes).

RESULTS

The geometric mean of maternal serum AFB1-lysine adduct concentration was 1.37 pg/mg albumin (95% CI: 1.30, 1.44 pg/mg albumin). Twenty percent of infants were of LBW and 32% were SGA. Sixteen percent of infants were stunted at birth. In addition, 13% of infants were born preterm. In logistic multivariate regression models, mean maternal serum AFB1-lysine adduct concentrations were significantly associated with SGA (OR: 1.13; 95% CI: 1.00, 1.27; P < 0.05).

CONCLUSIONS

Findings from this study suggest a small but significant association between serum AFB1-lysine adduct concentrations in pregnant women and SGA. Maternal aflatoxin exposure was not associated with other birth outcomes. These results highlight the need for future research on a threshold level of aflatoxin exposure needed to produce detectable adverse birth outcomes. This trial was registered at clinicaltrials.gov as NCT03312049.

Relationship Between Wasting and Stunting in Infants from Banke, Nepal (P10-002-19)

Objectives

Stunting and wasting in early life increase the risk of mortality. While assessed and diagnosed as individual conditions, these two forms of malnutrition often coexist within the same populations and possibly the same individual. The main objective of our analysis was to assess the magnitude of stunting and wasting among Nepali infants in the first 12 months of life and to investigate the association of early life wasting on later stunting.

Methods

For this analysis, we utilized anthropometric data collected in a longitudinal birth cohort study with 1675 maternal-infant dyads. Birth length and weight were collected within 72 hours of birth in 95% of the infants and 88% were followed through 12 months of age. Length, weight measurements were collected on the infants at 3, 6, 9 and 12 months of age. Measurements were converted to z-scores for weight-for-length (WLZ) and length-for-age (LAZ) using World Health Organization Standards. Outliers were defined as WLZ < -5 or >5 and LAZ < -6 or >6. Wasting was defined as WLZ < -2 and stunting as LAZ < -2. Statistical analyses were conducted in Stata® SE version 14.

Results

In the study population, 7%, 8%, 14% and 17% were wasted while 13%, 15%, 20% and 28% of infants were stunted at 3, 6, 9 and 12 months, respectively. Bivariate analyses showed significantly positive associations between wasting and stunting at 6, 9 and 12 months of age. After controlling for gender, birth weight, maternal height, maternal education, and household food insecurity, being wasted at any one visit during the first 9 months of life was associated with almost double the odds of being stunted at 9 months (AOR: 1.74 (CI: 1.23–2.48), P = 0.002), as was being wasted at any one visit during the first 12 months of life and stunting at 12 months (AOR: 2.21 (CI: 1.68–2.92), P = 0.000). The number of times wasted in the past year was not associated with higher odds of stunting.

Conclusions

Both wasting and stunting prevalence increased in Nepali infants in the first 12 months of life. Wasting was a significant predictor of stunting at 9 and 12 months of age. A single episode of wasting was sufficient to increase risk of stunting as observed by the lack of effect of cumulative wasting. Targeting and addressing the wasting observed is critical for long-term well being and development of Nepali infants.

Funding Sources

AID-OAA-L-1-00005, AID-OAA-L-1-00006, and AID-OAA-G-14-00002.

Multilevel analysis of individual, household, and community factors influencing child growth in Nepal

BACKGROUND

Childhood malnutrition and growth faltering is a serious concern in Nepal. Studies of child growth typically focus on child and mother characteristics as key factors, largely because Demographic and Health Surveys (DHS) collect data at these levels. To control for and measure the importance of higher-level factors this study supplements 2006 and 2011 DHS data for Nepal with data from coincident rounds of the Nepal Living Standards Surveys (NLSS). NLSS information is summarized at the district level and matched to children using district identifiers available in the DHS.

METHODS

The sample consists of 7533 children aged 0 to 59 months with complete anthropometric measurements from the 2006 and 2011 NDHS. These growth metrics, specifically height-for-age and weight-for-height, are used in multilevel regression models, with different group designations as upper-level denominations and different observed characteristics as upper-level predictors.

RESULTS

Characteristics of children and households explain most of the variance in height-for-age and weight-for-height, with statistically significant but relatively smaller overall contributions from community-level factors. Approximately 6% of total variance and 22% of explained variance in height-for-age z-scores occurs between districts. For weight-for-height, approximately 5% of total variance, and 35% of explained variance occurs between districts.

CONCLUSIONS

The most important district-level factors for explaining variance in linear growth and weight gain are the percentage of the population belonging to marginalized groups and the distance to the nearest hospital. Traditional determinants of child growth maintain their statistical power in the hierarchical models, underscoring their overall importance for policy attention.

Environmental variability and child growth in Nepal

Data from the 2011 Nepal Demographic Health Survey are combined with satellite remotely sensed Normalized Difference Vegetation Index (NDVI) data to evaluate whether interannual variability in weather is associated with child health. For stunting, we focus on children older than 24 months of age. NDVI anomaly averages during cropping months are evaluated during the year before birth, the year of birth, and the second year after birth. For wasting, we assess children under 59 months of age and relate growth to NDVI averages for the current and most recent growing periods. Correlations between short-run indicators of child growth and intensity of green vegetation are generally positive. Regressions that control for a range of child-, mother- and household-specific characteristics produce mixed evidence regarding the role of NDVI anomalies during critical periods in a child's early life and the subsequent probability of stunting and wasting. Overall findings suggest that the relationship between environmental conditions and child growth are heterogeneous across the landscape in Nepal and, in many cases, highly non-linear and sensitive to departures from normality.

Taxes and Bribes in Uganda

Using data from 433 firms operating along Uganda's charcoal and timber supply chains we investigate patterns of bribe payment and tax collection between supply chain actors and government officials responsible for collecting taxes and fees. We examine the factors associated with the presence and magnitude of bribe and tax payments using a series of bivariate probit and Tobit regression models. We find empirical support for a number of hypotheses related to payments, highlighting the role of queuing, capital-at-risk, favouritism, networks, and role in the supply chain. We also find that taxes crowd-in bribery in the charcoal market.

Land Use Change, Fuel Use and Respiratory Health in Uganda

This paper examines how biomass supply and consumption are affected by land use change in Uganda. We find that between 2007 and 2012 there was a 22% reduction in fuelwood sourced from proximate forests, and an 18% increase in fuelwood sourced from fallows and other areas with lower biomass availability and quality. We estimate a series of panel regression models and find that deforestation has a negative effect on total fuel consumed. We also find that access to forests, whether through ownership or proximity, plays a large role in determining fuel use. We then explore whether patterns of biomass fuel consumption are related to the incidence of acute respiratory infection using a cross-sectional data set of 1209 women and 598 children. We find a positive and significant relationship between ARI and the quantity of fuelwood from non-forest areas; a 100 kilogram increase in fuelwood sourced from a non-forest area results in a 2.4% increase in the incidence of ARI for children. We find the inverse effect of increased reliance on crop residues. As deforestation reduces the availability of high quality fuelwood, rural households may experience higher incidence of health problems associated with exposure to biomass burning.

Using satellite remote sensing and household survey data to assess human health and nutrition response to environmental change

Climate change and degradation of ecosystem services functioning may threaten the ability of current agricultural systems to keep up with demand for adequate and inexpensive food and for clean water, waste disposal and other broader ecosystem services. Human health is likely to be affected by changes occurring across multiple geographic and time scales. Impacts range from increasing transmissibility and the range of vectorborne diseases, such as malaria and yellow fever, to undermining nutrition through deleterious impacts on food production and concomitant increases in food prices. This paper uses case studies to describe methods that make use of satellite remote sensing and Demographic and Health Survey data to better understand individual-level human health and nutrition outcomes. By bringing these diverse datasets together, the connection between environmental change and human health outcomes can be described through new research and analysis.