Not me but a clise friend.
It is not as easy as just asking the doctors for it. The doctors assess you and tell you if you are suitable. As well as looking at your general health (it can be a dangerous operation), they will also assess your mental state. My friend passed and had the operation.
He has lost a lot of weight and appears much happier. When we go for meals, he often gets his meal wrapped up to take out as he cannot finish it. It hasn't however, stopped him binge drinking and taking on a lot of calories through alcohol, so I would rate it as being only partially successful.