Nutrition in school-age children: a rationale for revisiting priorities

Abstract

Middle childhood and early adolescence have received disproportionately low levels of scientific attention relative to other life stages, especially as related to nutrition and health. This is partly due to the justified emphasis on the first 1000 days of life, and the idea that early deficits and consequences may not be fully reversible. In addition, these stages of life may superficially appear less "eventful" than infancy or late adolescence. Finally, there has been historical ambiguity and inconsistency in terminology, depending on whether viewing "childhood" through physiologic, social, legal, or other lenses. Nevertheless, this age bracket, which encompasses most of the primary education and basic schooling years for most individuals, is marked by significant changes, inflection points, and sexually driven divergence in somatic and brain growth and development trajectories. These constitute transformative changes, and thus middle childhood and early adolescence represents a major and last opportunity to influence long-term health and productivity. This review highlights the specificities of growth and development in school age, with a focus on middle childhood and early adolescence (5 years-15 years of age, for the purposes of this review), the role of nutrition, the short- and long-term consequences of inadequate nutrition, and the current global status of nutrition in this age group. Adequate attention and emphasis on nutrition in the school-age years is critical: (a) for maintaining an adequate course of somatic and cognitive development, (b) for taking advantage of this last major opportunity to correct deficits of undernutrition and "catch-up" to normal life course development, and (c) for addressing the nutritional inadequacies and mitigating the longer-term consequences of overnutrition. This review summarizes and provides a rationale for prioritizing nutrition in school-age children, and for the need to revisit priorities and focus on this part of the life cycle to maximize individuals' potential and their contribution to society.

Keywords: adolescence; children; growth; malnutrition; middle childhood; nutrition; obesity; school age; stunting.

Figure 1

Major developmental life stages (in gray) and commonly used terminology for specific developmental stages as related to age. Modified and adapted from Bundy et al 2017 and Sawyer et al 2018

Figure 2

Growth trajectories in school-age years (gray-shaded area). Fat and fat mass: estimates. All others are medians. Compiled and adapted from Tanner and Davies 1985 (height velocity), Weaver et al 2016 (BMC gain), Veldhuis et al 2005 (fat and fat mass), US CDC (BMI). BMC: bone mineral content; BMI: body–mass index

Figure 3

Neuromaturational and cognitive development trajectories in school-age years (gray-shaded area). Compiled and adapted from Peterson et al 2021 (brain and gray matter growth), Tapert and Schweinsburg 2005 (neuromaturation process rate), Lee et al 2014 (brain region development), and Anderson 2002 (cognitive development executive domains)

Figure 4

The figure depicts key events in somatic and brain growth and development trajectories occurring in middle childhood and early adolescence. The timing is meant to show sequence, and the ages are best approximations. Divergence relates to differences between sexes. See text for related references. BMC: bone mineral content.