What time do you go to bed every night? According to a new study published by the Journal of Pediatrics, the time you go to sleep directly affects your risk for obesity later in life.
Researchers analyzed 977 children from the Eunice Kennedy Shriver National Institute of Child Health and Human Development’s Study of Early Child Care and Youth Development. The study tracked bedtimes of children around the age of four, and documented their height and weight. Children were then revisited at 15, where new body mass indexes and bedtimes were recorded.
The study found that 23 percent of preschoolers with a bedtime after 9 p.m. were obese in their teen years. To compare, 10 percent of children that slept before 8 p.m. became obese as teenagers.
“Preschool-aged children with early weekday bedtimes were half as likely as children with late bedtimes to be obese as adolescents,” said Sarah Anderson, lead author of the publication, “This was true even after taking into account other factors that we know are related to risk for obesity.”
While scientists know how duration of sleep can affect obesity, this is one of the first studies to put bedtimes in the spotlight. However, Anderson notes that there are previous studies published by the Journal of Pediatric Psychology that focuses on the relationship between bedtime and cognition.
“Other research has shown benefits for children’s behavior, cognitive development and attention,” she added, “Regular bedtime routines, including an early bedtime, also are linked to fewer sleep problems such as nighttime awakenings or difficulty falling asleep.”
In 2013, a three-week study involving children between the ages of 8-12 years old found that bedtimes also affected mental functioning. 32 children were told to either sleep one hour earlier or later than usual. At the end of each week, patients were asked to complete tasks that would test emotional functioning, math fluency and memory attention. Researchers discovered that going to sleep later in the night impaired a child’s mental performance on tasks.
“There is a vicious negative cycle, with sleep deprivation impairing emotional regulation and with impaired emotional regulation leading to increased stress and arousal, further interfering with sleep,” said Reut Gruber, director of the Attention, Behavior and Sleep Lab at Douglas Mental Health University Institute.
So what time should children go to sleep? Harriet Hiscock, associate professor at Murdoch Childrens Research Institute recommends:
- 7 p.m. for infants
- 7:30 p.m. for toddlers
- 8 p.m. for young children
- 8:30 p.m. for preteens
- 9-10:30 p.m. for teenagers