How much weight will you lose just eating fruits and vegetables for a week?

Has anybody tried this diet? I need to drop about 40 lbs and fast.I am 16, 5'3 and weigh about 170, goal weight 130. I know I need protein,so will drinking some milk fulfill that job? I'm planning just drinking banana & apple smoothie with raw oats for breakfast and eating salads for and dinner (no ranch :( ) I will walk a mile everyday and kickboxing for 45 mins. btw I don't plan to eat school lunch since its just chickens burgers and burritos etc. So will I lose weight and how much? Please no rude comments. Thanks