Blue light exposure at night may sabotage your keto diet efforts

Exposure to blue light at night may be sabotaging your weight loss and low carb dieting efforts, a new study has found. The research focused on rats that followed a diurnal schedule, meaning they were awake during the day and slept at night. When exposed to light from LEDs for an hour at night, the rats were found to have an increased sugar cravings and reduced glucose tolerance the next day.

Artificial light produced by smartphones, tablets, television screens, and other gadgets includes high levels of blue light. Exposure to this blue light later in the day, and particularly at night, has been linked by past research to various health issues, including reduced sleep quality.

New research recently presented at the Society for the Study of Ingestive Behavior (SSIB) in the Netherlands found that in rats with the same sleeping patterns as humans, a single hour of blue light exposure at night had significant effects on glucose tolerance and sugar cravings the next day.

The team found that male rats exposed to this artificial blue light at night drank higher quantities of sugar water compared to nights without the blue light exposure. Male rats were also found to have 'altered' glucose tolerance, something that could eventually lead to the development of pre-diabetes. Repeating this light exposure pattern over a long period of time may result in obesity and diabetes.

Study lead Anayanci Masís-Vargas explained:

Limiting the amount of time that we spend in front of screens at night is, for now, the best measure to protect ourselves from the harmful effects of blue light. In case it is necessary to be exposed to devices at night, I would recommend the use of apps and night mode features on the devices, which turn the screens more orange and less blue or the use of blue light filtering googles that are already available in the market.