Depends on the procedure. I think they’re doing more “banding” instead of the old staples.
There can be many adverse, unpredictable health problems related to absorbtion.
If you are restricted to meal portions and food selection, you would be better off doing a diet...temporary suffering instead of long term health problems.
Have you done a web search of Gastric Bypass testimonials?
I work with a couple of ladies who have had the surgery over the last eight or nine years. They lost a lot of weight initially, but then gained a good bit of it back.