What are the man and woman talking about?

M: Many people seem to be on a diet. Have you noticed that, Anna?
W: Yeah, I heard a lot of girls talking about diets.
M: A friend of mine, Linda, was once on an egg diet. She ate an egg for breakfast, an egg for lunch, and two eggs for dinner. She thought eggs were cheap, and eating eggs could make her slim.
W: Oh, my God! That would be bad for her health. Had she lost any weight?
M: Yeah, a little bit. But the problem is that she felt very sick. Then after one week, she had to give up. She said two days after eating eggs for three meals, she felt very dizzy. But she didn’t want to stop because she promised to herself that she would keep on doing that for one month. Her ideal weight is 45 kilos.
W: It is wise for her not to do that any more. It is true that eggs have a lot of protein, however, eating too many eggs is bad for the heart.
M: Yeah, it is true. I agree with you. On Wednesday, I went to see her. She looked very pale. She has been in bed for three days.
W: I am sorry to hear that. Tell her not to do that any more. Actually, the best way to lose weight is to eat less and exercise more.