The Surprising Impact Sunlight Has On Your Weight

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.


7 Little-Known Benefits of Sunlight

Your Seasonal Depression is Real and it’s Easier to Deal with SAD Than You Think

Woman Tries to Survive on Sunlight and Water Alone for 6 Months


Janice Thompson
Janice Thompson3 years ago

I have a strange allergy to the sun but I will see what I can do. Help is always appreciated when one is trying to get healthy.

Debbie Crowe
Debbie Crowe3 years ago

I guess I will have to get outside in the morning, instead of the afternoon from now on!

Debbie Bemister
Debbie Bemister3 years ago

Thank you.

Lauren Martin
Lauren Martin3 years ago

Really impressive! It is said in these studies that light is the most potent agent to synchronize our internal body clock that circulates some particular rhythms and it also regulates body balance. If this I was before attending the plastic surgery seminar, I would haven’t even thought of doing a TT and BA. I would have spent hours in sunlight and shed my pounds off. Lol!

Lois Sepahrom
Lois Sepahrom3 years ago

Interesting, after being stuck in the house all winter, I'm going to make it a point as soon as it is warm enough to have my morning coffee outside.

Genoveva M M.
Genoveva M3 years ago

What about people working nights and sleeping during the day hours?
If this study was completely true they would be all over weight, and believe me when I say, not everyone working night is over weight because of the lock of sun light. Is it the sun light good for the body? Of course it is, but it doesn't define your weight.
Bad food and the lock of exercise does.

Elena T.
Elena Poensgen3 years ago

Thank you :)

Kristina May
Kristina May3 years ago

A great reason to get out the office and go for a walk at lunch.

Sara Joaquim
Sara Joaquim3 years ago

Wow. This is impressive! I hope they work on this subject deeply, I want to learn more about it!

Barb Hansen
Ba H3 years ago