Although thinking hard uses calories, the energy burn is minimal. It's not enough to burn fat and cause weight loss. The brain is also an organ, not a muscle. Exercise can grow your muscles, which makes them burn more calories.

Do you burn calories when thinking?

While the brain represents just 2% of a person's total body weight, it accounts for 20% of the body's energy use, Raichle's research has found. That means during a typical day, a person uses about 320 calories just to think.

How many calories does your brain burn while studying?

The amount of energy spent in all the different types of mental activity is rather small, he said. Studies show that it is about 20 percent of the resting metabolic rate, which is about 1,300 calories a day, not of the total metabolic rate, which is about 2,200 calories a day, so the brain uses roughly 300 calories.