We’re always hearing about the problems of too much blue light on your sleep, but new research shows just how much of an impact it could be having on your overall health. From weight gain to low energy levels, that pesky evening phone call has a lot to answer for!

If you’ve been feeling off par, sluggish or out of shape, it might be time to dim the lights. Ensuring you spend your evenings in low and natural light could be the key to a healthy, and even slimmer you, suggests a study from the American Academy of Sleep Medicine.

What does blue light do?

‘Preliminary findings show that a single night of light exposure during sleep really impacts measures of insulin resistance,’ said lead author Ivy Cheung Mason, PhD. ‘Of course light exposure overnight can disrupt sleep, but our research suggests it may also have the potential to influence metabolism.’ In turn, this could lead to weight gain, and a higher waist circumference. ‘These results are important given the increasingly widespread use of artificial light exposure, particularly at night,’ said Dr Mason.

‘As humans, our body clocks have evolved to be awake during the day and asleep at night,’ says sleep expert Dr Neil Stanley. ‘For the vast majority of evolution, the only sources of light were the sun, the moon and potentially a campfire, so our ancestors would have been very ruled by natural light patterns.’

However, in today’s world of electronic devices such as phones, laptops, tablets and TVs, it’s probably no surprise that sleep patterns have changed. And not only can this mess with your body clock, but as the study suggests, could directly affect how shipshape your body is! But of course, we know we can’t go back to living in caves by firelight – and we understand that technology is a positive development and very much here to stay. So, we’ve turned to some of the country’s leading experts for their advice on the best ways to live a life full of light, colour (and tech) – and get quality, healthy kip too.

How can I cut down on blue light?

So what is it that makes different light have such an impact on the state of your sleep, and health? ‘The presence of light during the day is hugely important for helping us physically function and stay alert,’ says Dr Stanley. ‘However, with the rise of technology we are now, effectively, taking this light to bed with us.’ Specifically, this is the light from the ‘blue’ part of the spectrum, which is emitted from our electronic devices. It’s believed that the shorter wavelengths in blue light cause your body to produce less melatonin – the hormone that regulates sleep. These wavelengths suppress delta brainwaves, which induce sleep and boost alpha wavelengths, which create alertness. That’s great in the office, but rubbish in the bedroom!

Natural light helps you sleep at night

While you might spend most of your night-time routine in darker, softer light, brighter and natural light is still the key to a good night’s sleep. Exposure during the day boosts attention, improves mood, and strengthens circadian rhythms, meaning you’ll sleep better at night with a more regulated body clock. ‘Make sure you take advantage of any free time and get out in the sunlight for at least 20 minutes a day,’ says Medical Director of The London Sleep Centre, Dr Irshaad Ebrahim (londonsleepcentre.com).

Stop using your phone at night

It’s time we started viewing our tech in the same way as we look at sugary foods and put ourselves on a ‘tech-diet’. ‘Make sure you stop using your phone at least 30 minutes (but ideally an hour) before you’re due to go to sleep,’ says Dr Ebrahim. This will allow the effects of the blue light to dissipate and your melatonin levels to regulate – a sort of power-down hour. ‘Remember that this includes your television – many people think this isn’t as bad as light from your phone or other device, but in fact, it’s just the same. Newer LED TVs emit very strong blue light waves.’ Read our digital detox tips.

Use a light filter on your phone

If you really need to look at your phone nearer to bedtime, there are some ways to minimise the impact of the light. ‘Though there is little research into their effectiveness,
some blue light filters claim to help,’ says Dr Ebrahim. Apple’s ‘Night Shift’ is a built-in function on the phone, which can be scheduled to shift to warmer wavelength light on the screen in the evenings and then back to bright, blue wavelength light in the morning. There are also blue light-filtering glasses and screen protectors available, such
as the Ocushield blue light screen filter (from £14.99, ocushield.com).

Supplements for eye health

Research suggests carotenoid supplements may help strengthen your eyes’ ability to block blue light. Try Life Plan Mixed Carotenoids (£5.99, hollandandbarrett.com).

Red or amber lightbulbs can help you fall asleep

At the opposite end of the colour wheel to blue are warmer, amber shades, so surround yourself with these tones in the evenings. ‘Candlelight is ideal as it won’t disrupt melatonin production, but it’s not always practical,’ says Dr Ebrahim. ‘Opt for red or amber tinted bulbs or the standard incandescent kind as these give off a warmer light. Avoid blue-toned LED or halogen bulbs in your relaxing rooms as these give off the light that’s closest to daylight.’ And consider changing the bulb in your bathroom to a warmer light so you get straight back to sleep more easily after late-night loo trips!

Early nights help you lose weight

Getting to bed earlier might also be a way to control your weight, after a new study showed that ‘night owls’ have a tendency to have a higher body mass index. People with prediabetes who go to bed later, eat meals later and are more active and alert in the evening have higher body mass indices compared with those who do things earlier in the day, according to the University of Illinois at Chicago-led study.