The timing of children's light exposure during the day could influence weight gain. [Photo: Bigstock]

Is there a link between light exposure and kids’ weight?

31 August, 2016

By Staff Writer
Natural Health News

Natural Health News — Could exposure to artificial light have an influence on kids’ weight?

A study revealing light exposure plays a role in the weight of preschool children has been published by international research journal PLOS ONE.

Researchers from Queensland University of Technology Institute of Health and Biomedical Innovation and the Centre for Children’s Health Research, studied children aged 3-5, from six Brisbane childcare centres. They measured children’s sleep, activity and light exposure over a two-week period, along with height and weight to calculate their BMI, then followed up 12-months later

“We found moderate intensity light exposure earlier in the day was associated with increased body mass index (BMI) while children who received their biggest dose of light – outdoors and indoors – in the afternoon were slimmer,” said researcher Cassandra Pattinson.

What you need to know

» Studies into childhood obesity have identified several factors including high calorie meals and lack of exercise, which contribute to the problem.

» But a new study from Australia suggests that the timing of children’s exposure to bright light during the day is also influential.

» In this study children who received biggest dose of light – outdoors and indoors – in the afternoon were slimmer than those who did not.

At the 12-month follow-up the children who had more total light exposure at the beginning of the study had higher body mass. Light, the team concluded, had a significant impact on weight even after they accounted for body weight, sleep, and activity at the beginning of the study.

“Around 42 million children around the globe under the age of five are classified as overweight or obese so this is a significant breakthrough and a world-first.” said Pattinson

“Artificial lighting, including light given off by tablets, mobile phones, night lights, and television, means modern children are exposed to more environmental light than any previous generation. This increase in light exposure has paralleled global increases in obesity.”

Disrupting the circadian clock

Ms Pattinson said it is known the timing, intensity and duration of exposure to both artificial and natural light have acute biological effects in mammals.

“Animal studies have shown that timing and intensity of light exposure is critical for metabolic functioning and weight status. Our findings suggest that the same applies to us.”

“The circadian clock – also known as the internal body clock – is largely driven by our exposure to light and the timing of when that happens. It impacts on sleep patterns, weight gain or loss, hormonal changes and our mood.”