Epigenetic and life history approaches to child growth are centered on the relationship between the organism and its environment. However, defining and operationalizing the concept of environment is challenging, in light of the multiple variables that influence growth. Moreover, the concept of adaptation as it applies to child growth is seldom considered in the developed country context. This paper presents a study of children living in three neighborhoods in the City of Hamilton, Ontario, Canada. Two of the communities are considered adverse environments on the basis of low socioeconomic status, and their inner city, industrial location. In contrast to children living in the higher socioeconomic status area, children in these adverse environments display negative growth indicators, i.e., somewhat constrained linear growth in one and risk for overweight and obesity in both. Although both these inner city neighborhoods constitute adverse environments, they differ in ways that have a significant impact on children's growth. We argue for a definition of “adverse environment” that is broadly based, incorporating a range of physical, social, and temporal factors that are highly localized and sensitive to community-level influences on growth and health. As well, we consider whether higher prevalence of overweight and obesity is adaptive in any way to these adverse environments and conclude that they are more likely to be deleterious than adaptive in either the long or short term. Am. J. Hum. Biol., 2007. © 2007 Wiley-Liss, Inc.