What is the ideal body weight? Is a jockey the ideal weight or is a body builder? They both generally seem to be in pretty good shape to me.

Obviously, there's something wrong with this "ideal body weight" concept, and I think I know what it is: Humans aren't ideal.
Ideal means perfect. Humans aren't perfect. Therefore the ideal Human wouldn't be Human. S/He (probably genderless, actually) would be stronger, smarter, faster, would have tougher skin, better hearing, vision, smell, and taste, or perhaps not even have a material body at all.