I would have nrg shots remain as they are and change the way body shots work. Have body shots take a nibble out of whatever the other bot has. We're changing the concept of body altogether, might as well change the associated shot type.
However, chloroplasts and muscle shouldn't be recieved as they are. They need to be broken down into some other substance (you don't directly gain muscle by eating a steak.)
I'm not sure what that substance should be, though. We could introduce the idea of proteins, which are like the basic building blocks needed to build muscle and chloroplasts. Muscle and chloroplasts you get back are converted into proteins automatically. You can use proteins to build your own chloroplasts or muscle, for a little bit of energy maybe. You can build your own proteins using a certain set amount of energy. Maybe 100 nrg or something like that. Or maybe you convert a fat into a protien. The rules don't need to really make that much sense. You'd get very little nrg for breaking down proteins.
Although I think I suggested this a long time ago, and people weren't all that excited with the idea.