Chronic sleep deprivation from infancy to mid-childhood was associated with high overall obesity rates at age seven, found a study In Pediatrics released online today.
This is yet another study has been published in the journal about the importance of sleep for the healthy development of children. There have been a number of cross-sectional studies in which researchers asked a group of parents with children of the same age about sleep and health that have suggested a relationship between sleep and being overweight.
This new study, done at Massachusetts General Hospital and a number of departments at Harvard, followed over 1,000 children from six months of age to age seven. In this type of study, the same children are followed over different ages, and it is considered to be more informative and more reliable than a cross-sectional study. Once a year, mothers were asked about their children’s sleep and naps, and at age seven the children were weighed measured and evaluated for the study.
The findings are highly significant, clearly showing that children whose sleep was most curtailed or interrupted clearly had higher body mass index. The researchers defined curtailed sleep as shortened sleep relative to the average sleep duration. In the group with the most curtailed sleep, 34 percent of the children were classified as obese. In the group with the least curtailed, “best” sleep, only 6.8 percent of children were classified as obese.
In addition, it was found that sleep curtailment was also associated with lower socioeconomic status and minority status. Children in more disadvantaged families appear to have worse sleep. The authors speculate that sleep disruption and curtailment disrupts hormone regulation and the naturally occurring circadian rhythm, the natural ‘biological clock’ we all have. They also speculated that in lower income families, there is greater job stress, more hours worked by the parent and worse housing conditions. In more distressed families, children have more disrupted sleep and subsequent negative health outcomes.
These are not new findings. In this blog, we have earlier discussed another study in which it was found that children who watched more TV, did not eat family meals together and who did not have a reliable bedtime also were more likely to be overweight or obese. Thus, the new study replicates the findings about the relationship between poor sleep and obesity.
As has been suggested before, obesity may be more complex than food and exercise. Clearly, healthy routines including daily physical activity, a healthy diet as well as family meals, a reliable bedtime, and limits on screen time are essential for a healthy weight, as well as improved behavior and school performance.
So how do children sleep well? A bedtime routine which includes turning off the TV an hour before bedtime, reading at bedtime, and lights out in a quiet room is a great start. Routine and calm are the best ways to help a child sleep. While it may not seem important to most, we are increasingly finding that sleep is essential for brain and body development, and of all the things we do for our children, this may be one of the easiest for parents to achieve.