Fructose (fruit sugar) is still sugar, so could still cause the same risk of dumping: some fruits are very high in natural sugars (you can us Google to find out which ones), although that said natural fruit sugars are still better than refined sugar. I think if you go for NAS options as you suggest for example in orange juice, you may be OK, but I would read the sugar content on the label anyway....they might not be adding more sugar but it still may be really high in these natural sugars....I had a bottle of Tropicana Ornage Juice the other day and was amazed that it had 31g natural sugar content per 100ml bottle (didn't stop my guzzling it but then I'm still pre-op...would really make me have second thoughts post-op though!!!!!! I think this may be one of those things that you are going to have to try & see how you get on.