Obesity among American children has reached epidemic proportions. 34.8% of children in the 2003-2004 National Health and Nutrition Examination Survey (NHANES) sample were at risk for overweight (greater than 85%ile Body Mass Index, or BMI) or overweight (greater than 95%ile BMI) (37). Childhood obesity is an extremely strong predictor of adult obesity, poor cardiovascular health and a number of significant and lifelong health problems that manifest during childhood (38). Childhood obesity is thus extremely costly to society, reducing quality of life and burdening our health care system.

Though the epidemic of childhood obesity is widely recognized, the future consequences of overweight and at risk of overweight for the current generation of American children are not known. Preventing adult obesity by preventing or reversing childhood obesity may represent a major cost-effective strategy to improve present and future health in America, but no study has predicted future prevalence of obesity (and associated increases in cardiovascular and other morbidities) if additional efforts are not devoted to its prevention or reversal.

Aim 1 of this research proposal is therefore to apply data from longitudinal cohort studies on the tracking of obesity, the existing literature on the comorbidities associated with childhood obesity, and extant federal databases (NHANES, National Longitudinal Survey of Youth, Medical Expenditure Panel Survey and the National Hospital Discharge Survey) to predict the health and economic consequences of obesity in present and future cohorts of American children. Markov processes will be developed to describe each of the transitional probabilities of obesity over the lifespan, and multi-variable sensitivity analysis using Monte Carlo simulation will also be employed to develop a range that most accurately describes the possible consequences of childhood obesity.

Childhood obesity at its most basic level represents an imbalance between dietary intake and physical activity. Poor diet and physical inactivity are the leading etiologic factors of childhood obesity in America. In its report Preventing Childhood Obesity: Health in the Balance, the Institute of Medicine has identified a variety of promising approaches in childhood and adolescence to reducing morbidity of childhood obesity (39). Resources to combat childhood obesity are limited, and thus the most cost-effective interventions should be applied in order to reduce morbidity from childhood obesity, yet no study has systematically evaluated the relative cost-effectiveness of strategies to reduce morbidity from childhood obesity.

In Aim 2 of this research proposal, I will use data from the Iowa Bone Development Study to quantify the potential impact of various changes in diet and physical activity on future risk of obesity. I will then apply a decision-analytic model that compares the scenario in which no intervention is applied with the scenario in which an intervention that reduces children's television viewing, increases physical activity or improves diet is applied across the appropriate age cohort(s). The goal will be to assess the potential cost-effectiveness and cost-benefit profile of effective interventions identified by the Cochrane Group (40) that could reduce morbidity from childhood obesity by reducing children's television viewing, increasing physical activity or improving diet.

Traditional pediatric disease prevention has focused on identification of individual risk factor-disease relationships, and development of effective interventions to reduce risk. By executing the proposed research plan, I will become expert in the application of mathematical modeling and economic analysis to the design and evaluation of evidence-based interventions against obesity and other chronic childhood diseases and in the effective translation of science into evidence-based prevention.