I'm not sure if this is what you're asking, but this exact same question is on my science review. It says the answer is... *drum roll please*... your metabolism!
The hormone called as thyroid hormone. It is secreted by thyroid gland.
thyroid gland .
The amount of energy used by the body at rest is sometimes called the basal metabolic rate.
The brain uses the most energy in the body.
Energy in your body is used as a fuel to power your muscles. Your mouth uses muscles to move and thus it uses energy.
heat
When the body is being starved, it uses different means of finding energy sources within the body. When the body is extremely starved, it uses muscle mass as a last resort source of energy.
Thyroid gland determines the rate at which human body utilizes energy.
The amount of energy used by the body at rest is sometimes called the basal metabolic rate.
The brain uses the most energy in the body.
it converts carbohydrates into energy and uses them when you do physical activities
The body's resting rate of energy expenditure is known as the basal metabolic rate (BMR). BMR represents the energy required to maintain basic physiological functions while at rest, such as breathing, circulating blood, and regulating body temperature. It accounts for the largest portion of total daily energy expenditure.
the body uses fat for energy because the body needs to stay worm.
Glucose
Number of calories the body uses while at rest.
Energy.Carbs are converted to sugar in the body and utilized for energy.
Fat is stored energy. When the body needs extra energy - it uses up body fat.
The body uses fat which is a stored form of energy.
Energy in your body is used as a fuel to power your muscles. Your mouth uses muscles to move and thus it uses energy.