Study: How Preschooler's Bedtime Habits Affect Onset of Obesity Later in Life

A new study revealed that the time a child usually goes to bed can affect their chances of developing obesity later in their life.

The study, published in the Journal of Pediatrics, suggests that children who regularly go to sleep by 8p.m. are far less likely to become obese teenagers than preschoolers who tend to stay up all night. Furthermore, young children who have bedtimes after 9p.m. are two times more likely to be obese when they grow up.

For the study, the researchers followed 977 healthy babies born at 10 U.S. sites in 1991. These children were part of the Study of Early Child Care and Youth Development. When the children were about four and a half years old, their mothers were asked to report their typical weekday bedtime.

The researchers divided the children's bedtime into three categories: 8 p.m. or earlier, between 8 p.m. and 9 p.m., and after 9 p.m. Half of the participating children in the study fell in the middle category. On the other, hand, quarter of the study group fell in the first category, while the remaining quarter fell in the third category.

The children's bedtime categories were then associated with obesity when the children reached at an average of 15 years old. The researchers then discovered that one of ten children in the first category were obese teens, which is significantly lower compared to 16 percent of children in the second category and 23 percent of children in the third category.

"Children who stay up later often snack on high calorie foods, many watch TV, or use phones or tablets in their bedrooms, which further disrupts their sleep cycle," explained Dr. Meena Khan, a sleep specialist at The Ohio State University Wexner Medical Center, in a press release.

To determine if the emotional climate at home might be influencing the bedtime routines of the children, the researchers measured the "maternal sensitivity" by examining the mother-child interaction during a videotaped playtime. They then found out that regardless of the mother-child relationship, the link between bedtime and obesity remains strong. However, children who went to bed the latest and has mother with low maternal sensitivity have the highest risk of obesity.