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Study: Exposure To Morning Sunlight Helps Managing Weight

Posted by samzenpus on from the here-somes-the-sun-there-goes-the-pounds dept.

jones_supa (887896) writes "A new Northwestern Medicine study reports the timing, intensity and duration of your light exposure during the day is linked to your weight — the first time this has been shown. People who had most of their daily exposure to even moderately bright light in the morning had a significantly lower body mass index (BMI) than those who had most of their light exposure later in the day, the study found. It accounted for about 20 percent of a person's BMI and was independent of an individual's physical activity level, caloric intake, sleep timing, age or season. About 20 to 30 minutes of morning light is enough to affect BMI. The senior author Phyllis C. Zee rationalizes this by saying that light is the most potent agent to synchronize your internal body clock that regulates circadian rhythms, which in turn also regulate energy balance. The study was small and short. It included 54 participants (26 males, 28 females), an average age of 30. They wore a wrist actigraphy monitor that measured their light exposure and sleep parameters for seven days in normal-living conditions. Their caloric intake was determined from seven days of food logs. The study was published April 2 in the journal PLOS ONE. Giovanni Santostasi, a research fellow in neurology at Feinberg, is a co-lead author."

3 of 137 comments (clear)

  1. Vitamin D by Anonymous Coward · · Score: 3, Interesting

    Is this caused by Vitamin D perhaps? It would be interesting to compare to people on supplements.

    Here in Edmonton, Canada, my family Dr. was participating in a study where her patients were tested to Vitamin D. I ended up having to take 2000 IU a day. Not that I don't get outside; during about six months of the year you won't see any daylight from 5 pm to 9 am.

  2. correlation does not prove causation by Todd+Palin · · Score: 5, Interesting

    Could it be that the fat people are just lazy and get up later, and don't get outside early. Maybe fat causes people to get less light in the AM. See the problem with the headline?

  3. Re:Benjamin Franklin by The+Grim+Reefer · · Score: 5, Interesting

    Early to bed and early to rise, makes a man healthy, wealthy, and wise.

    I don't know about healthy. But late to bed, late to rise, seems to make you more intelligent and wealthier That study looked at 1000 people, rather than 54. If both studies are accurate, it looks like you can be smart, fat, and rich, or healthy, poor and stupid.