July 11, 2019

Obese toddlers are getting less sleep

UOW study finds connection between sleep patterns and obesity in children under three

University of Wollongong (UOW) researchers have discovered longer sleep durations may protect toddlers from obesity, but toddlers who spend more time napping may be prone to obesity.

Lead researcher and Early Start PhD candidate Zhiguang Zhang observed the sleep patterns of 202 toddlers under the age of three in the Illawarra over a one-year period.

Her findings were recently published in a prestigious international obesity journal.

Miss Zhang collaborated with UOW Early Start researchers João Pereira, Eduarda Sousa-Sa, Tony Okely, Xiaoqi Feng and Rute Santos.

She said the research may have implications for obesity prevention in young children.

“This is a piece in the puzzle of preventing childhood obesity,” Miss Zhang said.

“The obesity epidemic among children has been a major public health concern. It is vital to prevent excessive weight gain in the early years, and understand the risk factors. We know that a lack of adequate sleep may contribute to obesity in school-aged children, we now believe this may also be the case for children under the age of three.

“The good news is, parents have some degree of control.

“It is possible to change a toddler’s sleeping patterns, and create an environment where they will sleep more overnight.”

To track sleep, participating parents strapped motion detectors to their toddlers’ waists for a week-long period.

While the research found a possible connection between longer naps and higher body fat levels in toddlers, Miss Zhang stressed that naps were not the enemy.

“I’d strongly caution against placing a limit on nap times,” Miss Zhang said.

“Naps may reduce stress levels, improve motor skill learning and help their brains to function.”

The study also found no link between bedtimes, wake-up times and obesity, in contrast to a recent study of 8950 American pre-schoolers, in which children with later bedtimes were more likely to be obese and gain weight over a year than children with earlier bedtimes.

Ms Zhang suggested the sample size may have inhibited her study, and believes further research on toddlers must be done to obtain more conclusive evidence.

Ms Zhang’s revelations help to build a foundation of knowledge in what has been a relatively unchartered study area. There is a wealth of information linking sleep duration to obesity in adults and older children, however, just four other studies have focused on children under three, and none picked up an association between sleep duration and obesity.

‘The cross-sectional and prospective associations between sleep characteristics and adiposity in toddlers: Results from the GET UP! Study’ was published in Pediatric Obesity on 3 July.

The study was funded by an Australian Research Council grant. Miss Zhang is sponsored by a PhD scholarship from the China Scholarship Council and an International Postgraduate Tuition Award from University of Wollongong.