Study Ties Children’s Sleep Quality To Obesity Rates

A new study published in the journal Pediatrics suggests that infants and young children who regularly get insufficient sleep may face a greater risk of obesity by age 7.

Researchers from Massachusetts General Hospital for Children analyzed data from 1,046 children and gathered information from the children's mothers at 6 months, 3 years and 7 years. They also compiled information from questionnaires completed by the children when they were ages 1, 2, 4, 5 and 6.
The interviews with the mothers included questions about their children's sleep duration at night and during nap time.

When the children were age 7, the researchers gathered information on their height and weight, as well as their lean body mass, waist and hip circumference, total body fat and abdominal fat. The researchers then assigned sleep scores to the children based on their levels of sleep throughout the entire study period, with 0 being the highest levels of insufficient sleep and 13 being the lowest levels of insufficient sleep (no reports of insufficient sleep).
The average sleep score among the children was 10.2; more than half of children in the study did not experience much sleep curtailment over the study period. A little more than 4 percent of the children received a score of 0 to 4, 12.3 percent received a score of 5 to 7, and 14.1 percent scored 8 to 9. However, 28.8 percent received a score of 10 to 11, and 40.3 percent received a score of 12 to 13.

Researchers found an association between sleep curtailment and obesity, with sleep curtailment at all ages being associated with higher levels of measurements indicative of obesity. Kids who received the lowest sleep scores had higher total and trunk fat mass index, as well as higher waist and hip circumferences, compared with kids who received the highest sleep scores. There was also an association between lower sleep scores and socioeconomic factors, such as household income and maternal education. However, even after adjusting for these factors, researchers still found the association between sleep curtailment and obesity.

While this is hardly the first study to show an association between inadequate sleep and obesity, this study is unique in that it looked at sleep curtailment over time. Another recent study in the journal Childhood Obesity showed that one of the three most significant obesity risk factors for preschoolers is insufficient sleep (the other two are having a parent who is overweight or obese, and having parents who restrict the preschooler's eating because of weight control). The Society of Behavioral Medicine has also released a study which showed that sleep seemed to be associated with weight especially among low-income kids, with normal-weight children sleeping about a half hour more than overweight or obese children.

The study can't tell whether the missed sleep actually caused the kids to put on fat; it's possible that some factor the authors didn't account for was the real culprit. But there are several theories that might tie curtailed sleep to obesity, including the ebb and flow of hormones that control hunger.
Much of the research on mechanisms depends on findings in adults, and additional factors may be at play in kids, according to a lead author of the study. For example, a poor sleep routine at home also means that eating and meal patterns are probably also disrupted in those homes.

Dr. Jerald Simmons is active in treating pediatric sleep disorders and has long stressed the importance of proper sleep habits and patterns for kids. Childhood sleep disorders have also been linked to ADD and ADHD. For more information visit our website at HoustonSleep.net.