Study: Fewer Than Eight Hours of Sleep Associated With Higher Childhood Obesity Rates

Very short sleep among adolescents linked to a more than 70% increased risk of obesity/overweight in children, compared to those who get optimal 8 hours.

Fewer than 8 hours of sleep increased the risk among adolescents aged 12 to 16 years of being obese or overweight, according to findings presented at the European Society of Cardiology Congress 2022.

“Our study shows that most teenagers do not get enough sleep, and this is connected with excess weight and characteristics that promote weight gain, potentially setting them up for future problems,” said study author Jesús Martínez Gómez, a researcher in training at the Cardiovascular Health and Imaging Laboratory, Spanish National Centre for Cardiovascular Research (CNIC), Madrid, Spain, in a press release.

The American Academy of Sleep Medicine recommends that children aged 6 to 12 years sleep an average of 10 and a half hours. This decreases to a median of 9 hours a night for children aged 13 to 18 years.

The research team used these guidelines to group the study participants, categorizing patients who slept fewer than 7 hours as very short sleepers. The category of short sleepers slept 7 to 8 hours, and optimal sleep was 8 or more hours.

Based on this, Martínez Gómez led a study to see whether excessive screentime is related to poor sleep habits among adolescents and whether overweight/obesity are associated with sleep.

Looking at data previously collected from the SI! Program for Secondary Schools trial, the investigators examined the association between sleep duration and health in 1229 adolescents, with an average age of 12 years at baseline (50% boys, 50% girls).

Fitted with a wearable activity tracker, participant sleep was measured for 7 days over the course of 5 years—at age 12, age 14, and finally at age 16. The researchers determined overweight/obesity according to body mass index (BMI). They also calculated continuous metabolic syndrome based on healthier negative values to unhealthy positive ones, which included waist circumferences, blood pressure, blood glucose, and lipid levels.

Among participants 12 years of age, 34% slept 8 hours each night, which decreased to 23% by age 14 and 19% at age 16. Overall, boys slept less than girls. Quality sleep was also associated with duration, especially in teenagers, as those who slept longer experienced more sound sleep.

Among age 12 adolescents, 27% were overweight/obese. At age 14, it dropped to 24%, and further dropped to 21% among those aged 16 years. Overweight/obesity increased by 51% between age 12 and age 14 adolescents who were very short sleepers.

These percentages decreased among those identified as short sleepers, especially adolescents aged 14 years. Very short and short sleepers had higher metabolic syndrome scores as well.

“The connections between insufficient sleep and adverse health were independent of energy intake and physical activity levels, indicating that sleep itself is important,” Martínez Gómez said in the press release. “Excess weight and metabolic syndrome are ultimately associated with cardiovascular diseases, suggesting that health promotion programmes in schools should teach good sleep habits.”

He added that “parents can set a good example by having a consistent bedtime and limiting screen time in the evening. Public policies are also needed to tackle this global health problem.”

Reference

European Society of Cardiology. Insufficient sleep in teenagers is associated with overweight and obesity. EurekAlert! August 24, 2022. Accessed on August 24, 2022. https://www.eurekalert.org/news-releases/962238