Does the fluid a human body is suspended in affect its metabolism?

Humans cannot live in water because their skin provides minimal protection for prolonged periods. Perhaps if I understood your purpose for asking the question, it would make more sense to me. It seems very creative and interesting. Hypothetically speaking, the gravitational forces on the body would be less, because of buoyancy, but resistance in the water (compared to air) would be greater.. Is this a physics question? If it's a biological / homeostasis (maintaining of body temperature) question - the body cannot maintain it's temperature in water because the skin (which has keratin, a water repellent) is not able to keep the water out (or in) for extended periods, thus leading to a failure in body function and homeostasis. So, if I had to guess, I would say the person in the water would burn more energy, because their system would go into shock, or they would be trying to fight for survival.