For the first time, a study reports the timing, intensity, and duration of your light exposure throughout the day is linked to your weight. A team from Northwestern Medicine led the study which was published in the journal PLOS ONE.
The study found people who had the majority of their daily sun exposure to brighter light in the morning had a significantly lower body mass index (BMI) than those who had light exposure later in the day.
Study senior author Phyllis C. Zee, MD said, “Light is the most potent agent to synchronize your internal body clock that regulates circadian rhythms, which in turn also regulate energy balance. The message is that you should get more bright light between 8 a.m. and noon. Those with the study believe around 20 to 30 minutes is enough to impact BMI.
Morning light exposure was found to be independent of an individual’s physical activity level, caloric intake, sleep timing, age, or the season of the year. It also accounted for about 20 percent of an individual’s BMI.
“If a person doesn’t get sufficient light at the appropriate time of day, it could de-synchronize your internal body clock, which is known to alter metabolism and can lead to weight gain,” Zee said. She added that the exact way light affects body fat needs to be examined in further research.
Study co-lead author Kathryn Reid said, “Light is a modifiable factor with the potential to be used in weight management programs. Just like people are trying to get more sleep to help them lose weight, perhaps manipulating light is another way to lose weight.”
Those behind the study suggest getting more light exposure during the day, such as sitting near a window at work or school, if possible. Also, go outside for lunch or on a break. The weather is getting nice since spring is here again, so why not go out and enjoy it?
Light may not be the big weight loss secret, but surely getting a little extra sunshine can be nothing but good.