Use and Misuse of Stunting as a Measure of Child Health

Abstract

The term "stunting" has become pervasive in international nutrition and child health research, program, and policy circles. Although originally intended as a population-level statistical indicator of children's social and economic deprivation, the conventional anthropometric definition of stunting (height-for-age z scores <-2 SD) is now widely used to define chronic malnutrition. Epidemiologists often portray it as a disease, making inferences about the causes of growth faltering based on comparisons between stunted (i.e., undernourished) and nonstunted children. Stunting is commonly used to monitor public health and nutrition program effectiveness alongside calls for the "elimination of stunting." However, there is no biological basis for the -2 SD cutoff to define stunting, making it a poor individual-level classifier of malnutrition or disease. In fact, in many low- and middle-income countries, children above and below the threshold are similarly affected by growth-limiting exposures. We argue that the common use of stunting as an indicator of child linear growth has contributed to unsubstantiated assumptions about the biological mechanisms underlying linear growth impairment in low- and middle-income countries and has led to a systematic underestimation of the burden of linear growth deficits among children in low-resource settings. Moreover, because nutrition-specific short-term public health interventions may result in relatively minor changes in child height, the use of stunting prevalence to monitor health or nutrition program effectiveness may be inappropriate. A more nuanced approach to the application and interpretation of stunting as an indicator in child growth research and public health programming is warranted.