The importance of size and growth in infancy: integrated findings from systematic reviews of scientific evidence and lay perspectives

Abstract

Background Associations between growth and size during infancy and adult disease have led some to recommend that interventions in infancy might benefit lifelong health. Any such recommendations should be informed by both the scientific evidence for relationships between infancy and later outcomes and the views and opinions of those who care for babies. Methods Separate, but interlinked, systematic reviews were conducted of the epidemiological evidence relating infant size or growth to later health and of lay perspectives on infant size and growth. Findings were compared and integrated to consider policy implications. Results Lay and scientific perspectives both cast infant growth and size as an indicator of other aspects of an infant’s life, rather than being of fundamental importance. While the scientific literature is most often concerned with infants at the extreme ends of the population distribution, and towards long‐term outcomes, the literature on lay perspectives suggests a focus on defining the ‘normal’ range, and on current health. Conclusions Differences and similarities between scientific and lay perspectives on health can highlight areas of agreement, as well as areas of potential misunderstanding or miscommunication.