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. 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.