摘要:Objectives. Reduction of cigarette smoking is an important public health goal. However, lower smoking prevalence may be associated with increased obesity prevalence. I sought to estimate the effect of decreases in smoking prevalence on obesity prevalence in the United States population. Methods. I combined current weight data by smoking status from the 1999–2002 National Health and Nutrition Examination Survey (NHANES) with smoking prevalence data from past NHANES surveys to estimate weight status had smoking prevalence not changed. Results. Even relatively large changes in the prevalence of smoking were estimated to have little effect on obesity prevalence. For example, if smoking prevalence in 1999–2002 were at the higher 1971–1975 smoking level, the estimated 1999–2002 obesity prevalence would be 22.5% rather than the actual value of 23.9%, a difference of only 1.4 percentage points. Estimates for other weight categories were similarly small. Conclusions. Decreases in the prevalence of cigarette smoking probably had only a small effect, often less than 1 percentage point, on increasing the prevalence of obesity and decreasing the prevalence of healthy weight in the population. Reducing the prevalence of cigarette smoking is an important public health goal because of the strong association of tobacco use with disease and premature mortality. 1 , 2 As a result of intensive campaigns of public health information, social pressures, and environmental changes such as smoke-free restaurants and bars, smoking prevalence among adults in the United States has steadily declined. 3 , 4 One of the Healthy People 2010 goals (goal 27–1) is to reduce cigarette smoking among adults from 24% in 1998 to 12% by 2010. 5 Obesity is also a risk factor for many diseases and conditions, such as hypertension, hypercholesterolemia, and diabetes. 5 The prevalence of obesity has been increasing in the United States for several decades. 6 , 7 Two of the Healthy People 2010 goals are to reduce the prevalence of obesity among adults to 15% from 23% (goal 19–2) and to increase the prevalence of healthy weight to 60% from 42% (goal 19–1). Smoking is associated with lower weight, 8 and smoking cessation is associated with weight gain. 9 , 10 Reductions in smoking prevalence have been suggested as one of the factors associated with an increase in obesity. 11 This suggests the possibility that progress toward the public health goal of reducing cigarette smoking might potentially lead to increases in the prevalence of obesity, thus having an adverse effect on the goals of decreasing obesity and increasing the prevalence of healthy weight. My objective was to estimate the potential impact of changes in smoking prevalence on the prevalence of weight categories, including healthy weight and obesity.