What is normal, healthy growth? Global health, human biology, and parental perspectives.

Thompson, Amanda L

OBJECTIVES The widespread variation seen in human growth globally stands at odds with the global health perspective that young child growth should not vary across populations if nutritional, environmental and care needs are met. This paper: (1) evaluates the idea that a single standard of "healthy" growth characterizes children under age 5, (2) discusses how variation from this standard is viewed in global health, in human biology and by parents, and (3) explores how views of "normal" growth shape biomedical and parental responses. METHODS This paper reviews the anthropological, public health and clinical literature on the nature of child growth and the applicability of World Health Organization Multicenter Growth Reference Study growth standards across contexts. RESULTS The considerable variability in child growth across contexts makes it unlikely that any one framework, with issues of sample selection and representativeness, can serve as the model of healthy growth. Global health, human biology and parents differ in the emphasis they place on heredity versus environmental context in understanding this variability, but human biologists and parents tend to view a wider range of growth as "normal." Since both biomedicine and parents base their care decisions on their perceptions of normal, healthy growth, the comparative framework used has important implications for medical treatment and feeding practices. CONCLUSIONS A more nuanced approach that incorporates the biology of growth and its association with health outcomes across contexts is critical to identify patterns of healthy growth and to avoid over-reliance on a single standard that may pathologize variability.