Falling asleep in front of the telly is doing two bad things to you

Scientists found sleepers exposed to light levels equivalent to the glow from a television screen are more likely to develop depressive symptoms and extra weight

Couch potato Brits who fall asleep in front of the TV have been warned the habit is making them fat and depressed. As autumn approaches and the nights draw in, a new report has revealed two thirds of Brits nod off while watching the gogglebox.

Scientists found sleepers exposed to light levels equivalent to the glow from a television screen – an illuminance measurement of approximately five lux – were more likely to develop depressive symptoms over time.

The lack of darkness in the room “blunts” melatonin, the hormone that tells the body it is time to sleep, notes the report, and disturbs the body clock, while keeping our nervous system “on alert”.

This leads to those who drop off in the flicker of TV light to feel depleted and to crave junk food the next day.

The study said: “Lab tests show that just one night in a moderately lit room can leave you with poorer next morning glucose control – bad news for weight, energy and cravings.”

It pointed to US National Institutes of Health data, covering 43,000 American women, which found those who slept with a TV or bright lamp on gained up to 11lb (5kg) more in weight compared to those who kipped in dark rooms.

Over a period of six years, those who slept with the blue light emitted by TVs were more likely to be classified as overweight or obese than their counterparts who dozed off in the darkness.

The study, compiled by bed firm Bedsava, said: “Night-time telly might feel cosy, but it isn’t harmless. Nearly two thirds of adults admit they fall asleep with the TV on, turning bedrooms into glow-lit sleep zones linked to weight gain and a higher risk of depressive symptoms.”

A spokeswoman said: “Your bedroom should be cool, dark and quiet. If you like background sound, set a sleep timer and switch to white noise or radio, not a bright screen.

“It’s a small change that protects your weight, mood and sleep.”