Could Light In The Bedroom Be Why You’re Gaining Weight?

Women may be more at risk of weight gain from lights or tv at night.


Artificial light during sleep puts women at risk of obesity according to research led by Dale P. Sandler, who is Chief of the Epidemiology Branch and a senior investigator at the National Institute of Environmental Health Sciences in the USA.

We know sleep is a vulnerable element in our healthcare regime and and although diet and exercise play a part in helping sleep it now seems that artificial light is putting us at higher risk of becoming overweight.

Can sleeping with the lights on influence your weight?

How much a person weighs is down to a complex interplay of factors. The rate of obesity has nearly tripled across the globe since the mid-1970s, and the UK has two thirds of adults who are either overweight or obese.

We know the health risks for obesity including high blood pressure, abnormal cholesterol levels, type 2 diabetes, heart disease, stroke, osteoarthritis, some cancers, mental health problems, and all can cause mortality.

Diet and exercise are the most highly studied factors that contribute to the rising obesity epidemic. However, now scientists are looking at other elements such as genetics and sleep and a new study, which recently featured in JAMA Internal Medicine, points to another culprit: artificial light in our sleep environment.

The study involved 43,722 women who took part in the Sister Study, which looked at environmental risk factors and the chances of developing breast cancer.

When the researchers analyzed the data, they identified a correlation between increasing levels of light exposure and health outcomes at the beginning of the study.

The more light a woman experienced in her sleeping environment, the higher her body mass index (BMI) and waist to hip ratio were, on average.

At the follow-up point, women who had a television or light on in the room had a 17% higher risk of gaining 5 kilograms (roughly 11 pounds) or more compared with women who reported no light while sleeping.

They also had a 13% higher risk of a BMI increase of 10%. The risk of becoming overweight or obese was 22% and 33% higher respectively.

The associations held when Park took into consideration possible confounding factors, such as inadequate sleep, diet, and physical activity.

“The fact that the association between artificial light at night and weight gain remained after we controlled for sleep characteristics is important new information,” Park commented to Medical News Today.

Helpful information: 

Obviously why we gain weight is not just one thing: usually it is a combination of factors such as menopause, stress, our overall health, diet and exercise.

Unfortunately women at menopause are particularly vulnerable due to the fluctuations in hormones at this time and oestrogen dominance is linked to weight gain around the stomach, abdomen and thighs.

So any factor you can control – such as light in the bedroom, or from a screen at night, will all help.