How long has Jenny given up eating meat?

M: Well, we don’t need to hurry with lunch today, Jenny, so I think I’ll have some chicken or steak. What about you?
F: Oh, I just want to have some vegetables and fruits, maybe a glass of milk. Nothing more.
M: Why, Jenny? I remember once you said meat was your favorite.
F: Used to be. But I have decided to become a vegetarian. And in fact, I haven’t had any kind of meat for three days.
M: Are you kidding? A vegetarian! I think you will be sent to hospital because of mal-nutrition before you become a real vegetarian.
F: Come on, Johnny, what you have said only shows that you know little about vegetarian. A vegetarian may not necessarily get malnutrition because we can find all the nutrition our body needs in vegetables, fruits, cereals, nuts and bean curd.
M: But scientists also have warned people that there are still many kinds of proteins and some minerals, which can only be found in animals or fishes. But, all right, I won’t argue with you. Just wait and see how long you keep this habit.
F: What you mean I will give up halfway? Do you know why I made this decision?
M: Why?
F: Last weekend, I saw a TV program that really made me think.
M: Another one? You are always influenced by these things. Last time it was one about religion, and you thought about becoming a nun.
F: But this time, it is different. Johnny. Do you know there’d be no more famines if we used land to grow food for people instead of cattle? Do you agree that animals also have rights as humans? Do you know our health is at risk due to diseases of mad cow disease? And do you know...
M: All right, Jenny, don’t get over excited. Here’s your salad. Let’s change a topic, shall we?