Research shows a unhealthy sleep routine in children increases their risk of obesity

An Auckland University study reveals obesity in preschool children is linked to their behaviour towards sleep, eating and play time.

But Researcher Samantha Marsh says some young children find bedtime upsetting, because they miss their parents.

Marsh advises setting a timer and letting the child know you'll check on them once it beeps, adding more time each night.

She says eventually you can tell them you'll fold the washing and come back - and they'll trust you enough to fall asleep.