Why is sleep important? The National Sleep Foundation recognizes that sleep is food for the brain. During sleep, important body functions and brain activity occur. Lack of sleep can be the reason you to look bad, make you feel moody and perform poorly. A brain that is hungry for sleep will cause your teenager to have daytime drowsiness which can affect job or school performance and even be deadly if they fall asleep easy behind the wheel. When you do not get enough sleep, you are more likely to have an accident, injury and/or illness. How many hours of sleep do teenagers need? Read more »