Young children and infants who do not get enough nighttime sleep have a significantly higher risk of becoming obese later on in life - napping does not reduce the obesity risk significantly, reports a study published in Archives of Pediatrics & Adolescent Medicine, a JAMA/Archives journal.
Over the last 20 years obesity rates in the USA and many other countries has increased dramatically. According to the CDC (Centers for Disease Control and Prevention, USA), at the end of 2009 only Colorado and the District of Columbia had a prevalence of obesity under 20%, while 33 states had a prevalence of at least 25%. Prevalence rates for obesity in Alabama, Arkansas, Kentucky, Louisiana, Mississippi, Missouri, Oklahoma, Tennessee, and West Virginia were at least 30%.
As background in the article, over the last three decades, the authors report:
Obesity - defined as having age- and sex-specific body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) at or above the 95th percentile of national growth standards - has doubled among children aged 2 to 5 years and adolescents aged 12 to 19 years and has tripled among those aged 6 to 11 years. Evidence is accumulating from cross-sectional population studies to support a robust contemporaneous relationship between shortened sleep duration and unhealthy weight status in children and adolescents.
Using existing national, longitudinal and panel survey data collected for children and adolescents, Janice F. Bell, Ph.D., M.P.H., of the University of Washington, Seattle and Frederick J. Zimmerman, Ph.D., of the University of California, Los Angeles, examined 1,930 children up to the age of 13 years, with information collected on the same children in 1997 (baseline) and 2002 (follow-up).
The children were separated into two groups:
- 0 to 59 month age group (younger group)
- 60 to 154 month age group (older group)
At follow-up, 33% of the younger cohort and 36% of the older cohort were overweight or obese.
For the younger group, short-lasting nighttime sleep at baseline was linked to a higher risk of either obesity or overweight later on.
In the older group, baseline sleep was not linked to weight status later on. However, they did find that "contemporaneous sleep was associated with increased odds of a shift from normal weight to overweight or from overweight to obesity at follow-up."
They also found that in the older group, nighttime sleep at follow-up was linked to a slight increase in obesity at follow-up, while sleep duration five years beforehand had no significant effect.
The researchers wrote:
These findings suggest that there is a critical window prior to age 5 years when nighttime sleep may be important for subsequent obesity status.
(conclusion) Sleep duration is a modifiable risk factor with potentially important implications for obesity prevention and treatment. Insufficient nighttime sleep among infants and preschool-aged children appears to be a lasting risk factor for subsequent obesity, while contemporaneous sleep appears to be important to weight status in adolescents. Napping had no effects on the development of obesity and is not a substitute for sufficient nighttime sleep.
"Shortened Nighttime Sleep Duration in Early Life and Subsequent Childhood Obesity"
Janice F. Bell, PhD, MPH; Frederick J. Zimmerman, PhD
Arch Pediatr Adolesc Med. 2010;164(9):840-845. doi:10.1001/archpediatrics.2010.143
Written by Christian Nordqvist