The study also linked light sleepers to higher smoking rates, less physical activity, and more alcohol use.

The research adds weight to a stream of studies that have found obesity and other health problems in those who do not get proper shut-eye, said Ron Kramer, a Colorado physician and a spokesman for the American Academy of Sleep Medicine.

"The data is all coming together that short sleepers and long sleepers don't do so well," Kramer said.

The study released yesterday is based on door-to-door surveys of 87,000 U.S. adults from 2004 through 2006 conducted by the National Center for Health Statistics, part of the Centers for Disease Control and Prevention.

Such surveys cannot prove cause-and-effect relationships, so - for example - it is not clear if smoking causes sleeplessness or if sleeplessness prompts smoking, said Charlotte Schoenborn, the study's lead author.

It also did not account for the influence of other factors, such as depression, which can contribute to heavy eating, smoking, sleeplessness and other problems.

Smoking was highest for people who got less than six hours of sleep, with 31 percent saying they were current smokers. Those who got nine or more hours also were big puffers, with 26 percent smoking.

The overall U.S. smoking rate is about 21 percent.

Results were similar, though a bit less dramatic, for obesity: About 33 percent of those who slept less than six hours were obese, and 26 percent for those who got nine or more. Normal sleepers were the thinnest group, with obesity at 22 percent.

For alcohol use, those who slept the least were the biggest drinkers.

Many elderly people are in the group who get the least sleep, which would help explain why physical activity rates are low. Those skimpy sleepers who are younger may feel too tired to exercise, experts said.

Stress or psychological problems may explain what's going on with some of the lighter sleepers, experts said.

Other studies have found inadequate sleep is tied to appetite-influencing hormone imbalances and a higher incidence of diabetes and high blood pressure, noted James Gangwisch, a Columbia University sleep researcher.

"We're getting to the point that they may start recommending getting enough sleep as a standard approach to weight loss and the prevention of obesity," said Gangwisch, who was not involved in the study.