Busy thinking can burn more calories than mindless tasks
Your body is constantly burning calories. Calories are a unit of energy, and it takes a lot of energy to breathe, maintain blood flow, digest food, and regulate temperature. The brain controls almost all of the body’s functions, and it takes a lot of energy to do so.
This vital organ uses about 20% of energy 1the body burns at rest. So, let’s say you burn 1,600 calories at rest, about 320 calories will go to fueling the brain alone.
Like other organs in the body, blood vessels deliver energy to the brain primarily in the form of glucose (blood sugar). When an area of the brain is activated, blood vessels dilate to increase blood flow and nutrients such as glucose to meet the area’s higher energy needs.
Blood flow appears to increase to areas of the brain involved in more complex mental tasks. Researchers in a small study published in 2021 found that taking a more demanding cognitive test was associated with increased blood flow in the middle cerebral artery2whereas less demanding tasks or recreation do not.