Research supports that having a consistent bedtime in preschool is related to reduced risk of obesity in the tween years. That is, based on a cohort of children in the United Kingdom followed over time, researchers found that preschoolers who had inconsistent bedtimes were almost twice as likely to be obese by the time they were 11-years-old.
Although not causal, previous research from this group also supported the benefits of regular evening mealtimes and reduced screentime in relation to reduced risk for obesity in pre-teens.
Read more about this research by Sarah Anderson in an NPR article written by Allison Aubrey.