I see that Jenny beat me to it, but here's another link to the same blog: http://junkfoodscience.blogspot.com/2007/08/was-this-really-proof-that-bariatric.html
BTW, the lady who writes that blog is not afraid to question conventional wisdom. Here are some other examples: http://junkfoodscience.blogspot.com/2009/01/what-do-healthy-eating-and-lifestyles.html
http://junkfoodscience.blogspot.com/2008/11/null-series-healthy-eating-for.html
The death rate from obesity surgery, tracked over a ten year period, is much higher than the predicted death rate from obesity or diabetes would be. Slow-developing complications can lead to severe malnutrition, like that which killed Elliott Yamin's mother several years after her "successful" bypass.
Read this before you have the surgery: <a href="http://junkfoodscience.blogspot.com/2007/10/jfs-special-latest-research-on-actual.html">Junk Food Science: The Latest Research on Deaths from Bariatric Surgery</a>.
This surgery is "studied" almost entirely by the people who profit from it--a lot. It is an expensive surgery.
A supervised low carbohydrate diet is equally effective for many people and without the risk of death or nutritional disability.