I'm guessing you're increased training is starting make itself known--which is a very good thing. I have not noticed any effects of different foods on a ride, but I have noticed the effects if I got more dehydrated. Maybe eating the other stuff you're hydrating a little more??? I have noticed a big difference the next day if I drank a recovery drink immediately after a ride-R4, chocolate milk-something with a lot of carbs over protein.
Be careful and don't experiment too much with different food types on a ride. Make sure you go with stuff you know your stomach will easily digest-usually the simpler the better.
__________________
Ride your Ride!!