THE QUESTION Might the amount of sleep young children get affect how much body fat they have?
THIS STUDY involved 1,046 children. Their mothers reported the children’s daily sleep patterns periodically from the time the children were 6 months old until they were 7 years old. Based on a scale of zero (insufficient sleep) to 13 (sufficient sleep), with suggested sleep times based on standard age-based guidelines, the average child scored just over 10, with about 40 percent of the children getting the most sleep (12 to 13 on the scale) and 4 percent getting the least (zero to 4).
At age 7, the children were weighed and measured to determine their body mass index, waist and hip circumference, body fat and skin-fold thickness. Children who had consistently gotten the least sleep were 21 / 2 times as likely to be obese at age 7 as were those who routinely got adequate amounts of sleep. (Adequate was defined as 12 or more hours a day from age 6 months to 2 years, 10 hours or more for 3- and 4-year-olds, and nine or more for those age 5 to 7. Children who regularly got less than the optimal amounts of sleep had more abdominal fat and body fat overall and larger waist and hip measurements than those who consistently slept the recommended lengths of time.
WHO MAY BE AFFECTED? Young children. Today, about 17 percent of U.S. youths 2 to 19 years old are obese, triple the rate of the period when their parents were children. Excessive weight in children generally is attributed to eating too much and exercising too little, although other factors, including stress, family history and socioeconomic status, also may play a role.
CAVEATS Sleep data came from mothers’ responses in interviews and on questionnaires. The study did not determine why the children’s sleep was curtailed or whether improving sleep would affect their weight.
FIND THIS STUDY June 1 issue of Pediatrics.
The research described in Quick Study comes from credible, peer-reviewed journals. Nonetheless, conclusive evidence about a treatment's effectiveness is rarely found in a single study. Anyone considering changing or beginning treatment of any kind should consult with a physician.