A new study says a later bedtime may be linked with an increased risk of obesity for pre-schoolers.

The study, in Tuesday’s Journal of Pediatrics, encourages parents to maintain regular bedtime routines for their children.

Researchers found that children who routinely went to bed late had a wider waist and higher body mass index or BMI.

The year-long study looked at 107 children in Sweden who went to bed after 9 p.m.

A commentary on the article suggests other important factors like excess screen time, inadequate exercise, and bad general health habits in the family may also be contributing factors in early childhood obesity.

Other research has found that a shorter sleep duration is associated with obesity in childhood.

Researchers say a consistent bedtime routine for pre-school children appears to be more important overall than an early bedtime.