How does the man respond when the woman decides they should go on a diet?

W: John, we’ve got to go on a diet!
M: Oh, no, not again. It never works for me.
W: It would work if you listened to me and made an effort.
M: All right, what is it this time?
W: Well, first of all, we should plan a balanced diet. We should make sure that we’re getting all the necessary vitamins and minerals and things like that.
M: That sounds like homework!
W: Don’t worry. I’ve got a list of all things here and loads of recipes for all sorts of meals. Secondly, we shouldn’t try to lose weight quickly. It doesn’t work, because you lose energy and feel hungry all the time. I think it’s better to feel good and lose weight slowly.
M: So how long is this diet going to go on?
W: Until we feel we’re the right weight! Maybe each of us should give up something that is bad for us. You know, I should give up cakes and you should give up sugar in tea and coffee.
M: Ugh...
W: Oh, come on, you can do it! It’ll make life cheaper as well.
M: True, cakes are getting quite expensive!
W: And how about some exercise? We should take up swimming again. We both enjoyed that, didn’t we?
M: Yes, I would like to go swimming again. All right, let me think about it for a day or two.
W: Why think about it? Why not start now?
M: Because I’m hungry.