Abstract— Overweight in childhood sets the stage for a lifelong struggle with weight and eating and raises the risk of health problems, such as obesity, diabetes mellitus, hypertension, sleep apnea, and heart disease. Research from multiple disciplinary fields has identified scores of contributing factors. Efforts to integrate these factors into a single “big picture” have been hampered by the challenges of constructing theoretical models that are both comprehensive and developmentally adaptable. This article reviews select genetic and environmental factors influencing childhood overweight and obesity, then explicates an ecological model mapping these and other factors. The Six-Cs model extends previous theoretical work on childhood weight imbalance by acknowledging dimensions of factors specific to heredity as well as the environment, to activity as well as nutrition, to resources and opportunities as well as practices, and to development from birth through adolescence. This article concludes by discussing the model’s policy relevance and identifying important next steps for transdisciplinary research concerning child overweight and obesity.