Hidden Undernutrition: How universal cutoffs can fail to capture stunting in low and middle income countries
Year: 2018
Type: preprint
Abstract: Stunting, or impaired child growth due to undernutrition, has multiple negative health effects, making it a top global health priority. The current benchmark for classifying stunting assumes a universal model of growth with height-for-age z-score (HAZ) cutoffs set by the WHO. However, this universal model may hide hotspots of stunting if populations differ in HAZ in ways that are independent of undernutrition. We assess the potential magnitude of this bias by decomposing variation in HAZ from 1,406,609 children from 63 low- and middle-income countries into two components; 1) a component shaped by environmental inputs, poverty, infectious disease, inadequate sanitation, and healthcare access, and 2) a country-specific basal starting point that is independent of such inputs. After removing the effects of numerous environmental inputs, we find that different countries have reliably and substantially different basal starting points in average HAZ scores (a range of 1.7 SD). These country-specific starting points, which we define as basal HAZ, are not associated with key indicators of undernutrition (e.g., infant mortality and average calorie deficit). By contrast, average increases in HAZ above a country's starting point, which we define as accrued HAZ, show strong correlations with these same variables, suggesting that low accrued HAZ captures standard definitions of stunting as impaired growth due to undernutrition. Using these two components, we show how universal cutoffs can underestimate stunting in specific world regions (e.g., sub-Saharan Africa and the Caribbean), where children in even very deprived situations start off taller. As stunting is a high priority global health problem, standards that are sensitive to such population variation in healthy growth should improve efforts to target those most vulnerable to childhood undernutrition.
Source: arXiv (Cornell University)
Authors: Joseph Hackman, Daniel J. Hruschka
Institution: Arizona State University
Language: English
Subfield: Nutrition and Dietetics
Field: Nursing
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2809985142