UOW study connects sleep patterns and obesity in children under three

Researchers from the University of Wollongong have found that longer sleep durations may protect toddlers from obesity, however, in contrast, toddlers who spend more time catnapping may be prone to obesity.  

Toddlers under the age of three were studied for a year by PhD candidate Zhiguang Zhang, with sleep patterns recorded for 202 individuals. 

Miss Zhang collaborated with UOW Early Start researchers to conduct the work, the findings of which were recently published in Pediatric Obesity. 

With the growing obesity epidemic among children shown to be a major health concern, she hopes the research may have implications for obesity prevention in young children.

“It is vital to prevent excessive weight gain in the early years, and understand the risk factors,” Miss Zhang said, adding “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.” 

Outlining the role parents and early childhood education and care (ECEC) educators have in providing some degree of control in changing the outcomes for children, Miss Zhang said “it is possible to change a toddler’s sleeping patterns, and create an environment where they will sleep more overnight.”

Parents participating in the study 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 8,950 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.

While there is a large volume of research linking sleep duration to obesity in adults and older children, just four other studies have focused on children under three, and none picked up an association between sleep duration and obesity.

Miss Zhang’s work, The cross-sectional and prospective associations between sleep characteristics and adiposity in toddlers: Results from the GET UP! Study helps to build a foundation of knowledge in what has been a relatively unchartered study area.

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.