Why aren't you eating? You aren't doing your body any favors. You will put yourself into 'starvation mode' and your body will begin to hang on to every calorie once you begin eating again. You'll also ruin your metabolism like that and it will make it harder to shed weight at all. I saw you are planning this for 20 - 25 days? In that length of time, you'll F up your electrolytes and probably end up in the hospital. Just eat sensibly, get regular exercise, and stay healthy while you work on weight loss.