"Liver cleansing diet"
It's more of a healthy eating plan than anything else. Some people lose weight, others gain it.
It goes for a couple of weeks and in certain ones you can't eat chicken, just fish (no red meat, dairy and minimal sugar all the time). You start your day with a glass of water n lemon juice, and 15mins later drink parsley/celery/carrot juice (it actually tastes alright)
I didn't follow it perfectly because I needed a sugar fix during year 12 study, but when combined with exercise and no junk food in the house, it really does make you feel fresher (and lighter!)