Putting children to bed at the same time each night prevents them from piling on the pounds, according to new research.
Teenagers who had a rigid schedule growing up are less likely to be overweight, suggests the study.
The finding adds to growing evidence that insufficient sleep is fueling the obesity epidemic in youngsters.
Study co-author Dr Orfeu Buxton, a behavioral health and sleep expert at Penn State University, said: ‘Parenting practices in childhood affect physical health and BMI in the teenage years.
‘Developing a proper routine in childhood is crucial for the future health of the child.
‘We think sleep affects physical and mental health, and the ability to learn.’
Teens who had erratic bedtime patterns were more likely to suffer poor sleep, and in turn have issues with weight
HOW MUCH SLEEP CHILDREN SHOULD GET AT EACH AGE
Sleep.org has outlined the recommended amount of sleep for each age group.
Newborns (up to three months): 14 to 17 hours
Infants (four to 11 months): 12 to 15 hours
Toddlers (one to two): 11 to 14 hours
Preschoolers (three to five): 10 to 13 hours
School-age (six to 13): 9 to 11 hours
Tweens and Teens (14 to 17): 8 to 10 hours
The study was based on an analysis of more than 2,000 five-year-olds who were placed into groups depending on their sleep routines and followed for 10 years.
Just one in three consistently adhered to age-appropriate bedtimes between the age of five and nine.
Those who had no such routine had shorter self-reported sleep duration and higher body mass index (BMI) at 15 compared to those who did.
The study, published in the journal Sleep, supports existing pediatric recommendations that regular bedtimes are important for children’s health.
These should be determined by various factors such as when the child has to wake up to get ready for school and how long the journey is.
Dr Buxton said school start times aren’t determined by parents – but bedtime routines are.
He said: ‘Giving children the time frame to get the appropriate amount of sleep is paramount.’
It should provide enough of a ‘window’ to get an appropriate amount of sleep – even if the child doesn’t nod off right away, he said.
Lead author Soomi Lee, now assistant professor of ageing studies at the University of South Florida, said the study underlines the importance of continuity in sleep behaviours.
Those who had the best bedtime routines during childhood also had sufficient sleep duration in adolescence.
On the other hand those with the worst did not get enough.
Her team analyzed longitudinal data from the Fragile Families and Child Wellbeing Study, a national cohort from 20 US cities with 2,196 subjects.
Bedtime and sleep routines were assessed using mothers’ reports on their children when they were five and nine years old.
At 15, the participants themselves reported their height and weight which were used to calculate BMI.
Dr Lee said the study also highlights the importance of educating parents in bedtime parenting, especially for those in low-income households.
She said: ‘In our sample that includes a large proportion of low-income, low-education, and ethnic minority households, only less than one third of children had age-appropriate bedtime routines at age five and nine.
‘This raises a concern about development and health of children in disadvantaged households.
‘Future family interventions may need to include parental educations about sleep health, particularly focusing on parents with low income and low education.’
Additionally, future studies should focus on whether childhood sleep behavior interventions promote healthier sleep and weight in later life course stages, she said.
Earlier this year a chart was posted on UK lifestyle website Lifehacker showing five-year-olds should go to bed from 6.45 pm to 8.15 pm depending on their wake-up time.
Meanwhile, kids aged 12 should be asleep anytime from 8.15 pm to 9.45 pm.
If your five-year-old gets up at 6.30am, they’ll be ready to go to sleep at 7.15 pm.
But if they were up at the slightly later 7am, they’ll be ready to nod off at 7.30 in the evening.
While an eight-year-old who gets up at 6.45 in the morning will be ready to go to sleep at 8.15 pm, the same aged child who woke later, at 7.30 am, won’t be ready for bed until 9pm.
A previous study of almost 11,000 British children also found regular bedtimes stopped them from becoming overweight later in life.