A new study has linked a later bedtime with an increased risk of obesity for kids -- although the researchers say parents shouldn't rush to put their preschoolers to sleep earlier as a result, CNN reports.

Instead, concerned moms and dads should focus on maintaining a regular routine when it comes to scheduling meal and bed times, said Dr. Claude Marcus, a professor of pediatrics at the Karolinska Institute in Sweden and an author of the study, which published Tuesday in the journal Pediatrics.

The research, which was part of a wider study on obesity, focused on 107 children in Sweden, with 64 of the children having a parent who classified as overweight or obese.

The researchers monitored each child's weight, height and waist circumference from ages one to six; all of the children had similar measurements when the study started. Sleep was measured for seven consecutive days once a year for the length of the study by using a tracker worn on the child's wrist.

They found that children who habitually went to sleep late -- defined by the researchers as past 9 p.m. -- had a wider waist and higher BMI (body mass index) by the end of the study.

A major limitation of the study was the small number of children involved. However, the researchers were able to objectively measure sleep characteristics via the wrist tracker rather than relying on information relayed by parents and children, something Marcus said is often unreliable.