A new study shows that the majority of teenagers do not get enough sleep, and this is associated with weight gain and overweight, which potentially creates problems for them in the future.
The study looked at the relationship between sleep duration and health in 1,229 Spanish teenagers. The baseline mean age of participants was 12 years with an equal number of boys and girls. Sleep was measured over seven days using a portable activity tracker. Participants were categorized as very short sleep (less than 7 hours), short sleep (7 to 8 hours), and optimal sleep (8 hours or more).
Overweight and obesity were determined by body mass index. The researchers calculated a continuous score for metabolic syndrome ranging from negative (healthier) to positive (unhealthy) values that included waist circumference, blood pressure, blood glucose, and blood lipids.
At age 12, only 34% of participants were getting at least 8 hours of sleep a night, but at 14 and 16, this dropped to 23% and 19%, respectively. Boys tend to sleep less. The teens who slept the most also had better quality sleep, which meant they woke up less at night and spent more of their time sleeping in bed compared to those who slept the least. The prevalence of overweight/obesity was 27%, 24%, and 21% at 12, 14, and 16 years of age, respectively.
Scientists are currently investigating whether poor sleep habits are linked to excessive screen time, which could explain why older teens get even less sleep than younger ones.