Kids Who Skimp on Sleep Tend to...(xth grade. The researchers also measure...),Health

The researchers also took into account maternal education, race, the quality of the home environment and parenting skills to see if those factors affected a child's weight.

No matter what a child weighed in third grade, too little sleep correlated with being obese in sixth grade. And, short sleep duration in sixth grade also correlated with excess weight in sixth grade, according to the study.

Third-graders who got less than nine hours and 45 minutes of sleep a night had an obesity prevalence of about 20 percent, while those who got more than nine hours and 45 minutes of sleep had obesity rates of about 12 percent, Lumeng said.

Those who were short-changing sleep in third grade had 40 percent higher odds of being obese in sixth grade, and sixth-graders who weren't getting enough sleep were 20 percent more likely to be obese, compared to their well-rested counterparts.

Lumeng said the researchers weren't able to find a statistical association between quality of sleep and obesity. But, she said that without a lab-based sleep study, it's difficult to objectively assess the quality of sleep, so there may be an association that this study wasn't able to uncover.

Dr. Stephen Sheldon, director of the Sleep Medicine Center at Children's Memorial Hospital in Chicago, said he would've liked to see sleep studies so the researchers could have known more about the quality of sleep these children were getting, such as how much REM sleep did they get and how fragmented was the sleep?

But, he said, the bottom line is that "pediatricians and parents really need to start paying closer attention to sleep-wake habits. In this society,
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