Early in the life course: Time for obesity prevention

Abstract

One of the reasons for the intractability of childhood obesity is the underappreciation of the complexity and interconnectedness of contributing factors across the life course. A multilevel approach for obesity prevention takes into account individual risk factors that operate “above water” (family, neighborhood, policies) and the interaction with biology and “underwater” influences (genetics, epigenetics, physiology) and recognizes that these factors also interact across the life course, starting before birth. We organize this chapter to reflect phases of life course health development, prenatally through adolescence, that appear to be most important for the development of obesity and present key examples to illustrate important risk factors, mechanisms, and gaps in research. One of the challenges to understanding influences on obesity risk is the extent to which associations described in observational studies are causal. We present alternative methodological approaches, including sibling-pair design, maternal versus paternal effects, Mendelian randomization, cohorts with different confounding structures, and randomized controlled trials, that can help disentangle causal associations. We conclude with recommendations for future work on methodology, research in emerging areas, and implications for practice and policy based on the current evidence.