> And the only reason they consume that much energy is because the human body is inefficient at converting this heat to work. The human body does not convert h

> And the only reason they consume that much energy is because the human body is inefficient at converting this heat to work. The human body does not convert heat to work. We do something entirely different (look up the "ATP/ADP cycle"). But yeah there are certainly conversion losses in the conversion of egg sandwiches to labor. 25% or so. Which is actually pretty good; you won't be able to match that with a steam machine built over the weekend (start with solving the problem of setting eggs on fire?).