- Exposure to light at night may contribute to weight gain and rising rates of obesity.
- Even dim light exposure may cause a shift both in when you eat.
- When you eat may be important as what you eat and how much.
To avoid gaining weight, suggests a new study, we may need some darkness.
Mice exposed to light at night gained 50 percent more weight than mice whose nights were truly dark, the study found, even though the two groups ate equal amounts of food and got the same amount of exercise.
What seemed to matter most was the timing of their meals. With exposure to nighttime light, the study found, mice ate at times when they normally would be sleeping. That alone could have altered their circadian rhythms and led to weight gain. Dim lights had the same effect as bright ones.
While the mice in this study were nocturnal, the same could prove true in people. That would emphasize the need to shut the shades and turn off lights at night, including computers, TVs and smart phones -- not just to help with sleep, but to help us keep our figures.