New Study Shows How to Lose Weight While Sleeping

Sometimes no matter how healthy you try to eat, it can be hard to lose weight. But before you blame yourself, there's another culprit that may be robbing your body of its natural ability to burn fat as you sleep: Your LED lightbulb. Exposure to blue light in the hours before bed interferes with the body's natural fat metabolism, a new study from Japan has found, and LED bulbs emit blue light.

Screens such as your phone or TV in the bedroom emit blue light well. Blue light disrupts your sleep patterns and your melatonin production, which when it is working well, helps your body burn fat as you sleep. The implication is that we have broadly sabotaged our sleep patterns and natural fat-burning process. LEDs have spiked in popularity in the past decade or so due to their energy savings, and most Americans we know watch TV in the hours before bed.

That LED bulb in the bedroom? Plus the blue light from your computer? Your phone under the pillow? They all emit blue light that may be interfering with your body's natural fat metabolism, according to a new study that shows blue light at night can be detrimental to your metabolism. The assumption is if we all stopped exposing ourselves to blue light in the hours before bed, we could lose weight while sleeping.

The study finds that "blue light at night" is linked to weight gain, and that LEDs in the bedroom, and blue-light emitting screens before bed, are making it harder for you, me, and all of us to lose the weight we are trying to lose. The study authors from the University of Tsukuba published their findings in an article in the research news journal titled: "Turn Off the Blue Light!"

They concluded that "exposure to light with less blue before sleep is better for energy metabolism." Specifically, they found that LED lights in the hours before bed cause changes in melatonin that are associated with the body's fat oxidization process during sleep.

Nighttime Lighting: How does blue light affect sleep?

The researchers studied light-emitting diodes (LEDs), which emit blue light, versus organic light-emitting diodes (OLEDs). LEDs emit a large amount of blue light, which has been linked with negative health effects, including metabolic health, according to the study. OLEDs emit white light, which does not appear to affect metabolism during sleep, something the researchers at the University of Tsukuba aimed to address.

LEDs emit a large amount of blue light, which has been linked with negative health effects, including metabolic health, according to the study. OLEDs emit white light, which does not appear to affect metabolism during sleep, something the researchers at the University of Tsukuba aimed to address.

"Energy metabolism is an important physiological process that is altered by light exposure," says senior author of the study Professor Kumpei Tokuyama. "We hypothesized that compared with LEDs, OLED exposure would have a reduced effect on sleep architecture and energy metabolism, similar to that of dim light."

The study exposed 10 male participants to either LED, OLED, or dim light for four hours before bed and measured their energy output, core body temperature, fat oxidation, and melatonin levels as they slept. "The results confirmed part of our hypothesis," explained Professor Tokuyama. "Energy expenditure and core body temperature during sleep were significantly decreased after OLED exposure. Furthermore, fat oxidation during sleep was significantly lower after exposure to LED compared with OLED."

Fat oxidation (or burning) during sleep was positively correlated with melatonin levels following exposure to OLED, suggesting that the effect of melatonin activity on energy metabolism varies depending on the type of light exposure.

"Thus, light exposure at night is related to fat oxidation and body temperature during sleep. Our findings suggest that specific types of light exposure may influence weight gain, along with other physiological changes," says Professor Tokuyama.
Exposure to artificial light before sleep can influence your body's natural fat-burning ability during sleep. This is only one of many benefits of cutting artificial light before bed: studies have shown that going to bed early can decrease depression, and minimizing light intake can help you sleep earlier.

Bottom line: Reduce Blue Light Part of Your Bedtime Ritual

Exposure to blue light during the nighttime can mess with your metabolism. Try switching your LED bulbs to OLED ones in the bedroom, or stay away from blue light in the form of screens, phones, computers, and tablets in the hours leading up to bedtime. The negative consequences of light exposure before bed are just being discovered, so until further research is done, choose organic light sources before bed.

Looking for more ways to improve your sleep and your overall health? Read more about what to eat before bed to sleep better.