Caffeine Confuses Your Body's Internal Clock, Study Suggests

Drinking a cup of coffee at night may mess up your sleep in more ways than one: Caffeine not only keeps you awake but also affects your body's internal clock, which tells you when it's time to sleep and wake up, a new study suggests. The finding shows that caffeine "affects our physiology in a way that we hadn't really considered in the past," said Kenneth P. Wright Jr., a co-author of the study and director of the Sleep and Chronobiology Laboratory at the University of Colorado. In the study, f