People who are light sleepers tend to smoke more, exercise less, and use more alcohol than those who enjoy more restful nights, researchers say, and people who sleep less than six hours a night or more than nine hours are more likely to be obese.

The Associated Press reported May 7 that researcher Charlotte Schoenborn and colleagues from the Centers for Disease Control and Prevention found that smoking rates were highest among individuals who got less than six hours sleep, and those who slept the least also were the biggest drinkers.

The U.S. smoking rate is 21 percent, but 31 percent of those who slept less than six hours smoked, as did 26 percent of those who slept nine or more hours. Sleeping longer was not associated with heavy drinking, however.