Personally, I think your body needs vegetables. I did the fat fast, the meat fast...you name it. Nothing worked for a period of time... Sure, I lost a few pounds with each "fast" but felt yucky. I just watch my veggie consumption...never eating more than 3/4 cup of a veggie per day and there are days I have more salad greens than veggies (like today, had 3 cup salad and will have another salad with my roast beef tonight). I suppose if you eat adequate salad greens your body won't get constipated (which happens for those who eat mainly protein).