I once did some drastic stuff to lose weight really fast. I went on a regimen of nothing but tuna, mustard, baby carrots, and Wasa crisps for like 2 weeks. I lost 15 lbs. Yes, you read that right--15 lbs in just 2 weeks. I was so happy but I got to where I just could not do that anymore. I haven't eaten a Wasa crisp or tuna mixed with mustard ever again. I caved and ate a bunch of Oreos and regained my 15 lbs in about a week. When I did it the slower and sensible way (pretty much just adding more fruits and veggies to each meal and getting rid of a lot of the processed carbs), I did lose weight. It was a bit slower but at least it was something I could keep up with for life.