
Although the human brain makes up only about 2% of your body weight, it consumes roughly 20% of your body's energy while you're at rest. This energy powers billions of neurons that constantly send signals throughout the body. Even while you're sleeping, your brain remains active by processing memories, regulating breathing, and controlling other vital functions.
Because of its high energy demands, the brain depends on a continuous supply of oxygen and glucose. This remarkable organ is one of the most energy-hungry parts of the human body.
© National Institute of Neurological Disorders and Stroke