Research Shines Light on Weight Loss Strategy

Researchers have some simple advice for people trying to lose weight: set your alarm clock and head outdoors to get some early sunshine.

It might seem a little dubious, but a study published in the journal PLoS ONE found that exposing your body to light at the beginning of the day can lower your body mass index. Researchers from Northwestern University said 20 to 30 minutes of morning light was enough to affect a person’s BMI.

“The earlier this light exposure occurred during the day, the lower individuals’ body mass index,” said Kathryn Reid, one of the study’s author and research associate professor of neurology at Northwestern University Feinberg School of Medicine. “The later the hour of moderately bright light exposure, the higher a person’s BMI.”

Just as people try to get more sleep to help them lose weight, manipulating light may be another way to drop a few pounds. Of course, eating healthy foods and exercising regularly are two of the most effective ways to lose weight and maintain a healthy weight.

“Light is a modifiable factor with the potential to be used in weight management programs,” Reid said.

The study included 54 people whose average was 30. They used food logs to keep track of their caloric intake while wearing wrist monitors that measured their light exposure and sleep parameters. The influence of morning light exposure on body weight was independent of an individual’s physical activity level, caloric intake, sleep timing, age or season, a news release states.

“Light is the most potent agent to synchronize your internal body clock that regulates circadian rhythms, which in turn also regulate energy balance,” said study senior author Dr. Phyllis C. Zee. “The message is that you should get more bright light between 8 a.m. and noon.”

Source: Northwestern University news release