Emmaline .... if you are meaning that your age is 78 (which you don't mention again in your intro paragraph) .... I have to say the odds are not in your favour -- but do try, do at least go and ask.
The reason I say this is I know that the hospital I went to won't operate over the age of 65. I have heard of one person having a bypass at age 59 and one at age 62 ...... but those were the very oldest.
They make this criteria based on "how many years of value added life" will the bariatric surgery be adding to someone's life ..... and at 78 they would *statistically* be thinking only a few years .... even if you are the type who might make it to 98.
But don't give up without a fight and without trying -- you don't get anywhere in life if you don't *ask* in the first place, so go and see your GP and see what he says.
Again, the criteria in Norfolk could be different than that used by the hospital and the PCT who I went through.