Jun 02, 2014 04:02 PM EDT
Blue Light Exposure May Increase Hunger, Alter Metabolism
The manipulation of light exposure may be a novel method of altering food intake and metabolism, according to a recent study.
Researchers found that blue-enriched light exposure immediately before and during the evening meal may increase hunger and alter metabolism.
They found that blue-enriched light exposure, when compared with dim light exposure, was associated with an increase in hunger that began 15 minutes after light onset and was still present almost two hours after the meal. Blue light exposure also decreased sleepiness and resulted in higher measures of insulin resistance.
"It was very interesting to observe that a single three-hour exposure to blue-enriched light in the evening acutely impacted hunger and glucose metabolism," Ivy Cheung, co-author of the study and a doctoral candidate in the Interdepartmental Neuroscience program at Northwestern University in Chicago, Ill., said in a statement. "These results are important because they suggest that manipulating environmental light exposure for humans may represent a novel approach of influencing food intake patterns and metabolism."
For the study, researchers collected data from a group of 10 healthy adults with regular sleep and eating schedules who received identical carbohydrate-rich isocaloric meals. The participants completed a four-day protocol under dim light conditions, which involved exposure to less than 20 lux during 16 hours awake and less than 3 lux during eight hours of sleep. On day three they were exposed to three hours of 260 lux, blue-enriched light starting 10.5 hours after waking up, and the effects were compared with dim light exposure on day two.
Researchers said more research is needed to determine the mechanisms of action involved in the relationship between light exposure, hunger and metabolism.
The findings were recently published in an online supplement of the journal Sleep and will be presented Tuesday, June 3, in Minneapolis, Minn., at SLEEP 2014, the 28th annual meeting of the Associated Professional Sleep Societies LLC.
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