often people can't do what they want

You use "want" this way here, but then seem to deny this very usage to addicts (or to anyone who does not have organizational and motivational capacity to get what they "want").

It's true, but irrelevant.

Okay. A claim of irrelevancy is very different from a claim about truth, and truth is what you seemed to imply in the original comment:

You do what you want to do. (jmed: This entails Swimmer is wrong if she claims she wants to lose weight and doesn't/hasn't, a truth claim, not a relevancy claim.)

That said, I disagree that it is irrelevant, and you do, too, or else you wouldn't give her tips on how to make her second-order wants into first-order wants.