What do regular bedtimes and sufficient sleep for young children have to do with their health as teenagers? Quite a bit, according to a study that found an association between early childhood sleep habits and health later in life.

Researchers at Pennsylvania State University studied the habits of nearly 2,200 children across the country, tracking their bedtimes and sleep patterns among 5- to 9-year-olds. Those who didn’t have a bedtime routine by age 9 had a higher body-mass index and got less sleep at age 15 than children with established bedtime habits, the researchers concluded. The findings were reported in the journal SLEEP.

Parental instruction early in life, researchers noted, can influence a child’s health and weight into his or her teenage years. The findings reinforce just how crucial an appropriate amount of sleep is for children, they added.

Since bedtime can involve a confluence of factors, including how long it takes a child to fall asleep, the time school starts and how long it takes to get ready in the morning, experts suggest parents should consider all that and adjust bedtimes accordingly.

For children, continuity of sleep also played an important role in their well-being. Kids who had optimal bedtime and sleep routines in early childhood carried those traits into adolescence. The same held true for those children with less-than-ideal sleep habits.

Social factors also played a role: Less than one-third of young children in low-income and low-educations households had age-appropriate bedtimes — a situation that researchers said should make certain parents particularly vigilant.