Individual behaviors contribute to each of the nine domains in which the United States demonstrates a health disadvantage relative to other countries. Smoking contributes to adverse birth outcomes, heart disease, and chronic pulmonary disease, although smoking rates are now lower in the United States than in other countries and would explain little of the U.S. health disadvantage among adults younger than age 50. Unhealthy diet and low physical activity contribute to higher rates of obesity and diabetes. Alcohol consumption, other drug use, and unsafe sexual practices contribute to drug-related mortality, HIV/AIDS, sexually transmitted infections, and adolescent pregnancies. Substance abuse also contributes to injuries (unintentional and intentional), as do injurious practices and the prevalence of firearms in the United States. These conditions are causally interconnected. For example, obesity in early life can give rise to diabetes and, over time, the macrovascular complications of heart disease. Thus, health behaviors may play a pivotal role over the life course in promoting the conditions responsible for the U.S. health disadvantage.
Whether health behaviors in the United States differ significantly from those in other countries and the extent to which they explain the U.S. health disadvantage cannot be determined without better cross-national data. Further research is needed to define the specific behaviors that are predictive of adverse health outcomes, based on rigorous science, and to validate appropriate metrics and sampling methods for measuring those behaviors. Modes of administration, such as using accelerometers and other sensors instead of relying on self-report of physical activity, may also need to evolve. Countries would need to adopt a consistent battery of questions about health behaviors to enable meaningful international comparisons. Crime statistics would have to be more consistent across countries to understand international differences in violence. Historical cohort data on behavior patterns in prior years, or in prior decades, may be important in order to understand current disparities in the prevalence of diseases that result from a lifetime of sedentary behavior, unhealthy diet, or substance abuse.
Although no single behavior can explain the U.S. health disadvantage, the high prevalence of multiple unhealthy behaviors in the United States (Fine et al., 2004) may play a large role. Advocates of “personal responsibility” would note that people choose to engage in all of the behaviors discussed in this chapter, from eating sweets to carrying handguns, and they should be free to make those choices and bear the consequences. But such choices may not always be made “freely”: they are made in a societal and environmental context (Brownell et al., 2010). Parents may want to serve healthy meals but may not be able to do so without nearby retailers that sell fresh produce (Larson et al., 2009). They may want their children to