If it keeps you to a calorie intake level that is below that needed to maintain your weight, then it will work for weight loss. I know folk who have lost on it. Personally I think it doesn't teach you good eating habits so should be for short term only. And as Sophie points out, if it doesn't fill you up which will be the case until your stomach shrinks from anticipating less food, then you feel hungry and have trying to avoid eating on your mind all day. I think like many things, you can try it and see if it suits you, but I'd not recommend it as a long term activity.