Sleeping With Your TV Or Laptop On Could Lead To Obesity

New research has found that going to sleep with your TV on or laptop open may put you at risk of weight gain.

In a study of more than 43,000 women, researchers at the National Institute of Environmental Health Sciences found women who slept with an artificial light on in the bedroom also had an increased risk of weight gain and obesity.

Lack of sleep has long been associated with obesity, but until now, the association between artificial light exposure while sleeping and weight gain has been unknown.

sleeping with laptop on
Falling asleep to a movie or TV show could be helping you gain weight. Photo: Getty.

Researchers tracked women aged 35 to 47 across the United States and Puerto Rico over a five year period, measuring their body mass index (BMI).

After controlling for factors such as pregnancy or shift workers, as well as physical activity, diet, sleep duration and quality, researchers found that sleeping with the light on was associated with a weight gain of five kilograms or more.

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The findings, published in JAMA Internal Medicine, could have public health implications in regards to the current obesity crisis, researchers said.

Obesity affects 39.8 percent of adults in the US, according to government data; in Australia, two-thirds of adults (67 percent) are overweight or obese.

Obesity rates in Australia are on the rise. Image: Getty

"The two most common strategies for obesity prevention are promoting healthy diets and increased exercise levels," researchers said.

"However, adherence to healthy lifestyle habits is less than optimal, [and] there may be barriers to maintaining a healthy lifestyle, which may explain why obesity is not decreasing."

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Respondents reported exposure to artificial light at night (ALAN) from televisions, smart phones, computers, e-readers and tablets, which emit a short wavelength-enriched light or 'blue light' that previous research has linked to melatonin suppression and circadian disruption.

Others reported light shining in from porch lights, car headlights or street lights, as well as light from other rooms.

laptop bed
Exposure to artificial light was positively associated with a weight gain or 5kg or more. Photo: JAMA Internal Medicine.

Researchers did note that ALAN exposure might reflect a "constellation of measures" of socioeconomic disadvantage and unhealthy lifestyle behaviours, all of which could contribute to weight gain.

They were also unable to disentangle the relationship between ALAN and factors such as an unhealthy diet, sedentary lifestyle, stress and other sleep characteristics -- nor did they ask women why they slept with a light on.

"Our findings ... suggest that lowering exposure to [artificial night at light] while sleeping may be a useful intervention for obesity prevention," researchers said.

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