Overweight and at-risk-for-overweight are known to be multi-factorial disorders that involve biological, psychological, behavioral, and social risk factors that interact over time. Disentangling these risks is difficult because there may be critical periods during child development when risks exert their influence. There may also be cumulative effects for risks across time. The International Obesity Task Force has concluded that prevention is easier, less costly, and more effective than treating overweight and that intervention with children should begin prior to the onset and consolidation of risk-related factors. Developing effective strategies to interrupt processes that lead to overweight requires, in part, a thorough understanding of the natural history of this problem. While significant information about risk factors is known, there is little understanding of how these risks intersect and cumulate across the course of the child's life. Past research has relied primarily on cross-sectional studies and is limited in clarifying these pathway processes. The life course health developmental model provides a new framework. In this application, we investigate the development of childhood overweight using the life course health development model to determine if there are critical periods for risks and to examine the accumulation of risks across the child's life within biological, psychological, behavioral and social pathways. This study is important and relevant to nursing practice since nurses are a key health provider in assisting children in reaching healthy weight goals. The National Longitudinal Survey of Youth 1979 (NLSY79) and its associated child and youth studies are used to implement these analyses. The specific aims of this study are to: 1) Test the significance of the timing and accumulation of risks on the development and persistence of being at-risk-for-overweight or overweight in 24 month intervals between 24 and 191 months of age. 2) Simulate the effect of changes in modifiable risk factors on the prevalence of being at-risk-for-overweight or overweight among children aged 2 years through 16 years.3) Study the intergenerational pathways of weight maintenance between mothers and their biological children at 4 developmental stages to isolate the effect of shared environment from the effect of a shared biological disposition to weight states. This study is relevant to the public's health because we study the effect of various factors on the development of childhood overweight and identify factors to target for risk reduction.