The average adult needs between seven and eight hours of sleep each night for optimum health. Getting less than that, and getting more than that, signals health risks linked to poor lifestyle choices and excessive weight gain, according to the results of a door-to-door survey conducted by the Centers for Disease Control and Prevention’s National Center for Health Statistics.

The survey findings, released on Wednesday, are based on a survey of 87,000 American adults who were polled in 2004, 2005, and 2006. Survey questions were closely related to sleep habits and did not include questions about extenuating factors, such as depression, which may influence insomnia and poor choices pertaining to eating, exercise, smoking, and drinking.

The survey also did not produce any evidence of cause-and-effect associations, such as smoking causes sleeping problems or sleeping problems increase the urge to smoke.

People responding to the survey were ranked into three categories: those getting less than six hours of sleep each night, those getting proper sleep (seven to eight hours), and excessive sleepers, who regularly sleep nine hours or more each night.

For those getting less than six hours of sleep:

• 31% were current smokers (in the general US population, 21% are smokers)
• 33% were obese; and
• were the heaviest drinkers of alcoholic beverages

Of those getting proper sleep:

• 18% were current smokers
• 22% were obese; and
• drank less than light sleepers

Of those getting excessive sleep:

• 26% were current smokers
• 26% were obese
• drank alcohol similar to those getting proper amounts of sleep

People who slept in excess of nine hours per night were more prone to be physically inactive during times of leisure and are more likely to have serious health issues that hinders exercise.

The group getting the least amount of sleep included many elderly individuals and younger people who claimed to be too tired to exercise. One hypothesis for the light sleeping is that psychological problems, including stress, may make sleeping difficult.

Hormones that influence the appetite are linked to sleep, with too little sleep associated with an increased rate of high blood pressure and diabetes. It has been suggested that the recommendation for getting adequate sleep be included as a means of maintaining a healthy weight and to prevent obesity.