Info on juice fasting?

im a 5'9 215 lb 14 year old guy. i have done a couple 1 week fasts but ive went back to snacking allot and gained it back. im going to do a week long fast and get down to about 200, then ill eat a little for a few days, then ill go on the month fast. i plan on drinking allt of water, sunny d, apple juice and stuff like that. i need to lose 55 lbs to get down to a comfortable weight. what are some things i could do to speed up the fat loss and improve the diet