Having the TV on while sleeping could increase the risk of obesity, new research suggests.
Women exposed to artificial light at night were more likely to gain weight and become obese or overweight over the next five years, according to a study of almost 44,000 people.
The findings, published in journal JAMA Internal Medicine, suggest that eliminating lights and screens from the bedroom could be another way to tackle the obesity crisis, the study authors said.
The researchers, from the National Institute of Environmental Health Sciences in the US, followed 43,722 women aged between 35 and 74 years old, over a period of at least five years.
The group provided information on their weight, Body Mass Index (BMI), and any exposure to artificial light during the night.
Exposure to artificial light at night was linked with an increased risk of weight gain and the development of obesity, the study found.
Compared to those not exposed to artificial light, women who slept with a light or television on in the same room were 17% more likely to gain 5kg or more over the next five years.
They were also 22% more likely to become newly overweight and 33% more likely to become newly obese.
“These results suggest that exposure to artificial light at night while sleeping may be a risk factor for weight gain and development of overweight or obesity,” the authors said.
The researchers note that exposure to artificial light while sleeping might reflect other unhealthy behaviours, such as a sedentary lifestyle, and socioeconomic disadvantage.
However, commenting on the study, Professor Malcolm von Schantz, from the University of Surrey, said: “The findings make perfect biological sense.
“We know that light in the late evening will delay our body clocks.
“We know from experimental studies in people that light at night affects our metabolism in ways that are consistent with increased risk of metabolic syndrome.
“These new findings won’t change the advice to maintain good sleep hygiene, and avoid light and electronic distractions in the bedroom, but they add further strength to the case for this advice.”
How to improve your sleep. Top 5 tips
Neil Robinson, Chief Sleep Officer at bed company Sealy UK has a list of top tips to help you sleep:
1. Reset your routine
While we might all love a weekend lie-in, this can actually be detrimental to our sleep pattern. By allowing ourselves a later bed time, and in turn a later wake-up time on the weekends, our bodies are actually experiencing the same impact as they would from jet lag.
While you might be tempted to catch-up on lost sleep from the week, this can play havoc with your body’s circadian rhythm – the internal ‘clock’ which controls your energy levels. A regular bedtime on the other hand, will signal to your body that it’s time to feel tired, meaning you’ll be more likely to drop off to sleep no matter the day of the week.
2. Reduce your light pollution
Light is one of the key influencing factors in your natural body clock, which is why it’s important to limit the amount of light you’re exposing yourself to in the run up to bed. Melatonin, the hormone responsible for controlling our body clock, is produced in the brain at night, meaning exposure to light before bed can have a negative impact on our sleep by suppressing its production and preventing us from feeling tired.
The best way to avoid this is to keep the lights dimmed in your home in the hours before bedtime, and to limit the amount of blue light you’re exposed to from screens such as TV and mobiles for around 30 minutes before you plan to sleep.
3. Keep a sleep journal
A sleep diary is a great way to help you identify what factors in your life are helping and hindering your sleep. Make a note of everything from your sleep times and what wakes you up during the night, to the food you’ve eaten, your amount of screen time, and your day’s activity.
After keeping a record of your sleep for a month, you’ll be able to see any trends on things during the day that are impacting you at night.
4. Eat more avocado
Getting a good night’s sleep doesn’t stop with your diet. Make sure you’re eating and drinking the right stuff to ensure good quality slumber. Foods high in magnesium, such as avocado, bananas and almonds, could be exactly what you need to drift off into a deep sleep. This is because magnesium decreases levels of cortisol, the ‘stress hormone’, meaning that the more avocado we eat, the better we sleep!
5. Declutter your bedroom
If you’re already struggling to drop off to sleep at night, a cluttered bedroom is going to do you no favours. While a comfy and supportive mattress is crucial to helping you rest, the environment in which you sleep also plays a huge part in the quality of your slumber.
In fact, studies have shown that those who have a messy and cluttered bedroom have a worse night’s sleep due to increased stress levels – compared to those that keep their room nice and tidy.
Make sure to have a clear out and tidy to create the perfect sleep oasis that will leave you feeling calm and relaxed rather than stressed out