Walking in the bright morning may help you lose weight, new research found.

The small study found that people exposed to more light earlier, rather than later, in the day tended to be leaner than their peers, reports Newsmax Health.

The study included 54 adults. Twenty-six were male, and the average age was 31. A special monitoring device -- worn on the wrist -- measured light exposure and duration of sleep for seven days. The participants also kept food logs during the seven days they wore the monitoring device.

Those participants who were exposed to brighter light earlier in the day were the slimmest.

"For every hour later in the day that you reach 500 lux (unit of illuminance) that translates to an increase of 1.28 BMI. The earlier the light exposure, the lower the BMI," said study senior author Dr. Phyllis Zee, director of the sleep disorders center at Northwestern University Feinberg School of Medicine in Chicago.

There are a number of ways light might influence weight. One is by altering circadian rhythms -- the body's internal time clock -- to allow for better sleep. Morning light might also affect hormones that influence appetite regulation and metabolism, Zee said.

Even after the researchers controlled for other potentially slimming factors such as caloric intake, sleep duration/timing and the possibility that people getting early light exposure might be more active, light exposure still seemed to account for 20 percent of BMI, according to the researchers.

Zee recommended between 20 minutes and 30 minutes of bright morning light between 8 a.m. and noon.