Smoking cessation and body weight: evidence from the Behavioral Risk Factor Surveillance Survey.

There have been a rapid rise in obesity and a notable decline in smoking rates in the United States over the last few decades. The obesity epidemic spread rapidly during the 1990s across all states, regions, and demographic groups (Mokdad et al. 1998), and the prevalence has remained high, exceeding 30% in most age and gender groups during 2007–2008 (Flegal et al. 2007). Obesity is a major public health concern because it is associated with a long list of diseases such as type 2 diabetes, hypertension, dyslipidemia, certain forms of cancer, sleep apnea, and osteoarthritis. Overweight accounts for more than 350,000 premature deaths each year in the United States, second only to tobacco-related deaths (Mokdad et al. 1991). The accelerating spread of obesity has placed a tremendous burden on health care costs. The total direct and indirect costs attributable to overweight and obesity amounted to $117 billion in 2000 (U.S. Department of Health and Human Services [USDHHS] 2001). The Centers for Disease Control and Prevention (CDC) estimates that 46 million people or 20.6% of all adults (age ≥ 18) in the United States were current cigarette smokers during 2008 (CDC 1980). Cigarette smoking is the leading cause of preventable death in the United States, accounting for approximately 443,000 deaths or 1 in every 5 deaths each year (CDC 2004,c). Prevention of smoking initiation and cessation of smoking have become the national objectives to reduce morbidity and mortality and lower medical costs. Indeed, over the past 30 years, there has been a substantial decline in the proportion of adult smokers across all sociodemographic sub-populations. From 1955 to 2007, U.S. cigarette smoking rates fell from 57 to 22 percent in men and from 28 to 17 percent in women, with an overall rate of 20 percent for both genders in 2007 (Giovino et al. 1999). The last decade saw the smallest declines in cigarette smoking rates. CDC analyzes data from the 2008 National Health Interview Survey (NHIS) which indicate that during 1998–2008, the proportion of U.S. adult smokers declined by 3.5 percentage points—from 24.1 to 20.6 percent. The declining prevalence of cigarette smoking among adults has been attained by banning smoking in the workplace (Evans, Farrelly, and Montgomery 2006), restaurants and bars (ABC News, World News Tonight), intensive anti-smoking campaigns in the media (Flynn et al. 1995), and tax increases (USDHHS 1997). Although the overall health benefits of quitting smoking are unquestionable, the opposite trends of obesity and smoking in the United States have raised an important concern about an unintended effect of anti-smoking policies on obesity rates. Chou, Grossman, and Saffer (2009c, p. 585) claim that rising obesity is an example of “the price that must be paid to achieve goals that are in general favored by society.” Indeed, the association between smoking and body weight has become a central issue in the obesity literature, but the accumulating evidence is conflicting. In this study, we investigate whether quitting smoking leads to increasing body weight and to what extent. We compile data for current and former smokers (i.e., quitters) from the 2004–2005 and 2009–2010 Behavioral Risk Factor Surveillance Survey (BRFSS). The vehicle for our analysis is the treatment effect model (Barnow, Cain, and Goldberger 2005). To quantify the effect of smoking cessation, we calculate treatment effects for sub-samples of individuals. Our goal is to examine whether smoking cessation affects body mass index (BMI) differently by gender, between age groups, and among individuals with different lengths of time since quitting smoking.