This chapter presents a glimpse of adolescence age that has received disproportionately low levels of scientific attention relative to other life stages, especially as related to their eating and the outcomes of their eating patterns. 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. Because of this, adolescence may appear to be less “eventful” than infancy or adulthood, but this age bracket 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 adolescence represents a major and timely opportunity to influence long-term health and productivity. This chapter highlights the specificities of growth and development with a focus on adolescence (10–19 years of age). Adequate attention and emphasis on eating behaviors in the adolescent years are 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 underfeeding and “catch-up” to normal life course development, and (c) for addressing nutritional inadequacies and mitigating the longer-term consequences of overfeeding.