Incidences of obesity and extreme obesity among US adults: findings from the 2009 Behavioral Risk Factor Surveillance System

We used a weighted sample of 401,587 US adults from the 2009 Behavioral Risk Factor Surveillance System. Incidence calculations were based on respondent's height and current and previous weights. Logistic regression was used to examine associations between incidence and selected socio-demographic characteristics and behavioral factors.The overall crude incidences of obesity and extreme obesity in 2009 were 4% and 0.7% per year, respectively. In our multivariable analyses that controlled for baseline body mass index, the incidences of obesity and extreme obesity decreased significantly with increasing levels of education. Incidences were significantly higher among young adults, women, and adults who did not participate in any leisure-time physical activity. Incidence was lowest among non-Hispanic whites.The high incidence of obesity underscores the importance of implementing effective policy and environmental strategies in the general population. Given the significant variations in incidence within the subgroups, public health officials should prioritize younger adults, women, minorities, and adults with lower education as the targets for these efforts.The prevalence of obesity among adults has more than doubled in the past three decades, and obesity continues to be a public health concern [1,2]. One of the objectives of Healthy People 2020 is to reduce the proportion of adults who are obese [3]. It is well established that obesity is related to reduced quality of life, increased risk for premature death, and increased risk for many chronic diseases, including coronary heart disease, hypertension, stroke, Type 2 diabetes, and certain types of cancer [4,5]. Obesity is also associated with increased health care costs. It has been estimated that obesity was associated with almost 10% of annual medical spending and that obesity-related medical costs reached $147 billion in 2008 [6].Numerous studies have examined the prevalence of obesity and extreme obesity, with finding