Detox Question

I just have a quick question.
Ok so my mom for as long as I can remember has been on diets. About in september, she started going to the gym. She goes to the gym every single day and also has a personal trainer. She has always eaten really healthy. She ate fat free cottage cheese, fat free yougurt, cream of wheat and ate everything in proportion. She is the skinniest she has ever been. But she is also 55, and I do not know if being that skinny is ok. Anyways, she did a seven day detox about two weeks ago, which it totally ok. But now that the detox is over, she is still eating like she was on it. She is not taking any of the colon cleansing pills, but she is still eating like she is on the detox. She has a list of all foods to eat at meals and it is exactly like the detox. Example is one serving grain for breakfast. She will eat oatmeal and has barely and stuff. However, in the list of protiens to eat, there is no meat. There is just tofu and beans, which is ok, but she is not a vegetarian. She has also taken dairy right out of her diet. I am not sure if dairy is good or bad for you, but she was never eating bad dairy. It was always fat free everything and one percent milk. Anyways, my question is is if it is healthy to stay on the detox diet or not?