If you are going no-sugar, you might try coconut water. Actually, to be honest, I don't know it's sugar content, but it's natural and supposedly is chock full of electrolytes. I have considered getting some of this to keep in my bottles for long rides - but my problem is I just never know when I'm going to be on a long ride and never plan accordingly (I ride until I don't want to anymore, which could be 10 miles or 50).

If you are going low-sugar are you also going low-carb? I found when I first when low carb, having Luna bars on hand all the time was great. Now however (6 months in) I can have a cup of coffee, set off for a 50 mile ride with just water, and be fine when I get home. I often don't get hungry again for many many hours (6+ usually) and have not yet suffered any ill health effects. It just takes a little patience to reset the way your body fuels itself - I took it easy on my rides until I was sure my body was good enough at burning fat and not dependent on sugar to keep me going.