The Brain Never Stops

THE BRAIN IS SPONTANEOUSLY ACTIVE Surprisingly, the brain uses about 20% of the body’s energy at all times. That’s right: about one-fifth of everything you eat is for your brain. Figure 1 shows the energy consumption of the upper body and head. The dark areas show body parts that use a lot of energy while resting without movement. The brain uses a lot of energy, so it appears very dark in the image. This is also true of the heart, which needs a lot of energy to continuously keep beating. Nevertheless, the brain appears darker and thus uses more energy than the heart, the skeletal muscles, or any other organ. The brain’s high energy needs show that it is very active at all times.