Although the number of cigarette smokers has decreased over time, around 15 percent of adults in the U.S. smoked in 2015. The health risks of smoking are widely known in the U.S., with even smokers acknowledging the harmfulness of tobacco use. Smoking increases the risk of developing lung cancer among men by 25 percent and slightly more among women. It also increases the risk of both coronary heart disease and stroke by four percent.
In contrast to the decrease in tobacco use, the problem of weight and obesity continues to be prevalent in the United States. The percent of the population that is obese has risen steadily over the last decade, with 31.3 percent of adults reported to be obese in 2017. This increase in obesity is due to various factors, including unhealthy eating habits and a lack of physical activity. Over 20 percent of the entire adult population in the U.S. is considered physically inactive, with rates as high as 32.5 percent in the state of Arkansas. The health risks of being overweight include high blood pressure, kidney disease, heart disease and stroke, and diabetes.
Even a natural activity, like sex, can contain health risks if not practiced safely. Rates of some sexually transmitted diseases, such as syphilis and gonorrhea, have increased in recent years, with 23 new cases of syphilis reported per 100,000 population in 2015. A surprisingly large percentage of U.S. adults aged 18 to 29 had never been tested for an STD as of 2015, although the tests are fast, easy, and sometimes free. One of the best ways to protect against STDs is by practicing safe sex. However, between 2011 and 2015, an average of 33.7 percent of men aged 15 to 44 stated that they used a condom during their last sexual intercourse in the past year, compared to just 23.8 percent of women.