Hi Hans,

Sounds right to me. I suppose it depends upon how heavy limbs were because you would have to also account for the displacement in weight between biological legs and mechanical ones. Caloric requirement can be roughly estimated by weight (although to a good extent depends upon how much of that weight is muscle vs. fat).

So we can do a rough calculation to figure this out.

A male weighing 140 pounds at 5'5 who is moderately active requires roughly 2300 calories a day. http://walking.about.com/cs/ca…..alcalc.htm

If you assume that each leg weights 15 pounds, but that the mechanical legs weigh exactly the same, then you would calculate caloric requirements for a male at 110, in which case caloric requirements fall to approximately 2000 a day.

However, if the mechanical legs weighted less or more, then more or less calories would be needed in direct proportion to how active a person is. If the person never leaves bed then the caloric requirements are still 2000. If they are very active they will need slightly more, just like you need more energy to walk around with ankle weights.

If the mechanical legs were somehow powered by electricity then I suppose you would end up in a situation where the person with them would have the caloric requirements of someone of the same biological weight who didn't move very much.

Overall, though, it seems there wouldn't be that much of a difference. Probably appetite would decrease but who knows because the body does mysterious phantom limb things.

-Nikki