Intro:
Obesity is well established as a cause of multiple diseases that put excessive strain on healthcare resources. This is particularly true in the United States where obesity levels are among the highest in the world. However, forecasting future trends in obesity prevalence can be problematic given the difficulty associated with accurately quantifying the effect of the many risk factors that have been documented for obesity. In this study, a model is presented to forecast future adult obesity prevalence based on the current childhood obesity prevalence and the conditional probability of adult obesity given childhood obesity.
Hypothesis:
Adult obesity prevalence can be forecast based on current childhood obesity and the likelihood of the former given the latter.
Methods:
The annual change in historical (1975-2016) childhood (ages 5-19) obesity was calculated to ascertain a gender-specific trend. To forecast the prevalence of adult obesity (ages 20-59) in coming decades the model relied upon published age-specific probabilities of adult obesity given childhood obesity. To forecast the annual change in ten-year age-groups of obese adults these probabilities were then applied to the annual change figures derived from the historical childhood obesity data. The model used the linear regression of childhood obesity, from 1996-2016, to extend the forecast and determine a year in which the annual change in adult obesity became negative. Such a forecast provided an age-and gender-specific year in which the obesity epidemic in adult Americans comes to an end and prevalence begins to decrease.
Results:
By using historical childhood obesity data and the probability of adult obesity associated with childhood obesity the model forecasts the American obesity epidemic in males ages 20-29, 30-39, 40-49, and 50-59 to stop increasing and begin decreasing in 2048, 2054, 2059, and 2064 respectively. Likewise, the model estimated obesity prevalence will cease to rise in adult American females about a decade earlier with forecasts for ages 20-29, 30-39, 40-49, and 50-59 to be 2037, 2043, 2048, and 2053 respectively.
Conclusions:
In conclusion, adult obesity in the United States, like most documented disease epidemics will reach a point, beyond which the prevalence is expected to fall. The model was built to handle the difficulty associated with quantifying the effect of the multiple risk factors and the well documented period effects linked to obesity. The proposed model successfully used historical childhood obesity data and the correlation between childhood and adult obesity to forecast when obesity in the United States will cease to grow and start to decline.
Impacts of Federally Funded State Obesity Programs on Adult Obesity Prevalence in the United States, 1998-2010
