There are various types of surgery now available, most of them just restrict and cut off a part of your stomach.  It used to be when I was a kid that the only real option you had was to actually have a gastric bypass or have your stomach stapled.  I knew one girl who got it, but realistically speaking they generally don’t actually let anybody under 18 get it, and they are supposed to greatly restrict adults who actually qualify for it.  However, they now have other options such as the lapband surgery. 

They just put a small band in your stomach instead of actually sewing it off.  With gastric bypass you can actually burst it, and there are various problems with for example vitamin deficiencies.  With lapband surgery, they can actually move it around, and therefore they can go in and actually adjust it to your needs.  It accounts for a significantly smaller amount of surgeries.  But it does work the same way in some ways.  Likewise, gastroplasty actually staples and uses a band to divide the stomach in two.  It is actually extremely rare and uncommon.  But likewise, it does actually work and frankly accounts for less than 1% of surgeries in general.