its kind of cleaning your body from bad and unhealthy food and toxins. for example: this weekend ive eaten really unhealthy so im compensating it with two days of really strict dieting, which will consist of only fruit and water . i dont say its the best way to loose weight, but it is very affective and not dangerous if you only do it for a short period of time. still, its better to eat normal all the time and never over/under eat.