What is the most metabolically active(utilizes the most amount of energy to function) organ in the human body?

Question

Human body referred is regardless of gender,age and any normal physiological changes which can occur(healthy,ill,gestation periods.................etc)

Answer 1

the brain

Answer 2

It would have to be some type of muscle, like the heart. The brain can utilize glucose as an energy source directly, so it does not require the molecular changes to generate energy as other types of tissue. You could think of your brain as a muscle, since it is primarily made of protein.

Answer 3

It's the brain, of course... (the control room, so to say).  According to an article in the Scientific American magazine (see below), it "uses up to 20% of the body's total haul".