Source: Monatsschrift Kinderheilkunde  |  Posted 9 years ago

There is a strong inverse association between late bedtime or short sleeping hours and childhood obesity.

"Compared with children with 10 or more hours of sleep, the adjusted odds ratio was 1.49 for those with nine to 10 hours of sleep, 1.89 for those with eight to nine hours of sleep and 2.87 for those with less than eight hours of sleep," Japanese researchers report.

The investigators led by Dr. Michikazu Sekine of the faculty of medicine at Toyama Medical and Pharmaceutical University in Toyama City, surveyed and collected anthropometric data on 8,274 children aged six to seven years living in Toyama prefecture in June and July 1996, adjusting for age, sex, parental obesity and other lifestyle factors.

Researchers defined the 4,194 boys and 4,080 girls as obese if they had a body mass index (BMI) greater than the age- and sex-specific cutoff points linked to adult overweight. BMI was defined as kilograms divided by the square of height in metres or more. They set 25 kg/m