Why Does Your Body Burn Calories While You Sleep?

Imagine your body is like a house that never turns off the lights. Even when you are asleep and dreaming about flying, your heart is still beating, your lungs are breathing in and out, and your brain is thinking about what happened today. This uses up energy! Scientists call this basal metabolism. It is the fuel your body burns just to stay alive.

Think of a refrigerator. Even if it is empty, it has to work hard to keep the inside cold. Your body does something similar. Your brain is like a computer that never shuts down. Your stomach is busy digesting food from dinner. Your muscles are keeping you warm in your bed.

If your body did not burn calories while you slept, you would feel weak and tired when you woke up. Eating before bed gives your body extra fuel for this nighttime work. This is why sleep is important for staying healthy! You grow bigger and stronger even while you rest because your energy helps fix tiny parts of your body.