MINNEAPOLIS -- Exposure to blue light before and during your evening meal may affect how much you want to eat, according to a small new study.
Compared to exposure to dim light, exposure to blue light spurred higher hunger levels starting just 15 minutes after the light exposure. And those hunger levels stayed higher for nearly two hours after the final bite.
"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," study co-author Ivy Cheung, a doctoral candidate in the Interdepartmental Neuroscience program at Northwestern University in Chicago, Illinois, said in a statement.
In the study, 10 healthy adults were exposed to dim lighting for two days in individual bedrooms in a hospital setting. On day three, the participants were exposed to blue-enriched light from commercially available light boxes while doing seated activities like reading or doing homework before and during their evening meal, Cheung told The Huffington Post. Participants rated their hunger stronger after blue-light exposure than after dim light exposure, she says.
Exposure to blue light has long been known to affect sleep, likely due to its disruptive function to the body’s natural production of the sleep hormone melatonin. And in our constantly connected society, we're probably getting more blue light exposure than we realize. Skimping on sleep has also been shown to increase hunger and calorie consumption.
But it's still too early to connect these ideas, Cheung said. When it comes to sleep, blue light exposure and hunger, "I definitely think there could be an interaction," she told The Huffington Post, but the results from the current study don't provide conclusive information. Future research could examine what effect prolonged exposure to blue light at mealtime could have on both hunger and sleep, she noted.
The research, published in an online supplement of the journal SLEEP, was presented Tuesday, June 3, at SLEEP 2014, the 28th annual meeting of the Associated Professional Sleep Societies.