Study: Blue light emitted by iPhones and iPads can make you fat

“Using a computer or smartphone at night can cause us to pile on the pounds, new research has revealed. The study found a link between blue light exposure – blue light is emitted by smartphones and tablets – and increased hunger,” Emma Innes reports for The Mail. “It found that exposure to the light increases hunger levels for several hours and even increases hunger levels after eating a meal.”

“Results of the US study show that blue-enriched light exposure, 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,” Innes reports. “Blue light exposure has also already been shown to decreased sleepiness in the evening increasing the risk of insomnia.”

“Study co-author Ivy Cheung, of Northwestern University, in Chicago, said: ‘A single three-hour exposure to blue-enriched light in the evening acutely impacted hunger and glucose metabolism. 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,'” Innes reports. “The findings are published in the science journal Sleep and were presented today at an annual meeting of the Associated Professional Sleep Societies in Minneapolis.”

Read more in the full article here.

MacDailyNews Take: The study group comprised 10 healthy adults over a 4-day period.

A more comprehensive study is absurdly easy to imagine.


  1. So at least some of the 10 people got hungry while being exposed to blue light from 15 minutes to two hours after eating?

    So don’t sit in the dark using your iPhone. There, problem solved.

    1. Good point. F.lux is very good, although it conflicts with similar applications and ColorSync profiles.

      SO! If you’re paranoid about blue lights making you FAT, or you just have a penchant for believing every bad science article foisted into the public eye, GO GET F.lux! Highly recommended.

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