Hi Sylvia,
My Doc told me the same thing because my pre-surgery weight was over 300 lbs. He said that I would have better results with GB, but I didn't want to do it. I felt the band would be better for me and I liked the idea that it didn't have to be permanent and that I wouldn't risk the problems that come with it like malabsorbtion and dumping. Anyway, I had the band and the same Doc did my surgery on Sept. 19th and I'm down to 241 as of today. Not knowing the medical reasons behinds your Docs advice, I think the choice should be yours. I'd ask him if he feels if it's still medically safe for you to go forward with the band and if so, then I'd stick to your preference.
Hope that helps!