We will combine 7 high- quality national longitudinal cohorts into a synthetic cohort followed from birth to age 55 and estimate obesity dynamics, including the age and timing of obesity onset, age-specific obesity incidence, obesity duration and intensity, weight fluctuations, and cumulative exposure to unhealthy weight. Analysis will be estimated for the U.S. population overall and by race, ethnicity, poverty level, and rural/urban residence.

To date, there have been no estimates of the number of years Americans spend obese or in unhealthy BMI states in childhood through early adulthood. Using multistate life tables, we will employ the results produced in Aim 1 to estimate cumulative exposure to multiple high BMI levels during childhood and young adulthood for the U.S. population overall and by race, ethnicity, poverty level, and rural/urban residence.

We will link the dynamics of BMI during childhood and early adulthood from Aims 1-2 to risks of diabetes, cardiovascular, metabolic, and gastrointestinal diseases and to quality of life measures in adulthood. This aim will provide explicit estimates of the health effects that obesity and BMI dynamics early in life are having on current U.S. cohorts.

We will quantify disparities in obesity dynamics and exposure to high BMI experienced by youths across race, ethnicity, SES, and rural/urban residence. We will then quantify the extent to which obesity dynamics during the first decades of life contribute to observed disparities in diabetes, cardiovascular, metabolic, and gastrointestinal diseases and quality of life, using regression-decomposition approaches.

Using the estimates from Aims 1-4, we will develop a simulation to model the effects of interventions aimed to reduce childhood obesity on national burdens of adult disease and disparities in disease across race, ethnic, SES, and rural/urban groups. We propose to conduct a state-of-the-art, hypothesis-driven study to determine whether there are biological, environmental or behavioral factors influencing NIDDK disease outcomes across the lifespan. The project will advance our understanding of the racial and ethnic differences in incidence and prevalence of obesity and other NIDDK diseases and their progression, and will provide new bases for evaluating policies and treatments.