want175

I want to know how much am I likely to lose if I choose this surgery. The doctor told me 50 pounds (I weigh 225... that would be fantastic) but most of the information I read online says either "between 31 and 54 percent of excess weigh" or "about 50% of excess weight." Why the discrepancy? What is "excess weight?" My so-called ideal weight is 160. Is excess weight the difference between my current weight and my ideal weight? Is it something else? I'm also wondering why the surgeon is so optimistic? I would be disappointed if I did this and only lost 25 pounds. I've lost that much before, though I wasn't able to maintain it. I would do this if it lead to a very dramatic loss of weight. Can anybody give me the straight dope?