Not long, considering that’ll provide no nutrients.

about 40 days. he wouldnt be standing after 2 weeks though

Given vitamin supplements and assuming he is monitored for metabolizing his own organs, 180 days would be possible; however, it would likely result in a whopping case of the gout.

is this a real question?!

Or are you thinking of going anorexic on us?

Okay, as a biologist I gotta say this… people experiencing starvation go into a defense mode, a long painful process. First, they lose muscle mass as the body breaks down these tissues for energy. It wants to break muscle down before fat, because muscle burns more calories, fat uses nothing. Now if you work out, you are building lean muscle, and the fat will dissipate to provide support to the muscles. However, this requires nutrients.

Catalysis is the process (medical condition) of a body breaking down muscles and other tissues in order to keep vital systems working – vital systems such as the nervous system and heart muscle (myocardium). Catabolysis will not begin until there are no usable sources of energy coming into the body.

Vitamin deficiency is also a common result of starvation, often resulting in anemia, beriberi, pellagra, and scurvy. These diseases collectively may cause diarrhea, skin rashes, edema, and heart failure. Individuals are often irritable and lethargic as a result. (not so pretty, with the diarrhea and skin problems and all)

Atrophy (wasting away) of the stomach weakens the perception of hunger, since the perception is controlled by the percentage of the stomach that is empty. Victims of starvation are often too weak to sense thirst, and therefore become dehydrated.

All movements become painful due to atrophy of the muscles, and due to dry, cracked skin caused by severe dehydration. With a weakened body, diseases are commonplace. Fungi, for example, often grows under the esophagus, making swallowing unbearably painful.

The energy deficiency inherent in starvation causes fatigue and renders the victim more apathetic over time. Interaction with one’s surroundings diminishes as the starving person becomes too weak to move or even eat.

So, no, he won’t just loose all the fat and be hot… he’d be a weak mass of pain for years.