The effects of changes in smoking prevalence on obesity prevalence in the United States

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.