it's my personal opinion that it's actually easier to go "cold turkey" into absolutely nothing but water. the thing about allowing yourself the Watermelon is that you will be constantly reminding/tempting yourself with flavour. when you stop all food, your hunger actually shuts down after a few days. but if you are still consuming some type of food, you will probably feel hungry all the time. and you might start saying to yourself, "well, i'm already eating watermelon, so an apple wouldn't make much difference... and now i'm eating apple and watermelon, so it probably wouldn't hurt to have a salad..." do you see what i mean? that's probably what would happen to me, anyway! not that that would be a BAD thing, but it certainly wouldn't be considered fasting, if that's what your ultimate goal is.