I would Bring some of your own fuel & a couple different things. I brought dried apricots for the full, which is how I trained for their high potassium, well I had the flu and that was the last thing I could stomach so held out for the gu on course, which was perfect for how I felt that day. I don't like bananas which they have out for the full so passed on those. They do had out little chocolate bars at Studios which I ate. Next January I am packing at least 4-6 of my own Gus for the full and half probably 3, and something salty which I haven't figured out yet, maybe a few pretzels just in case I need the pick me up. I actually took m&ms from a stranger on the way to ESPN in Jan cause I was so hungry, the flu sickness really messed my appetite up which is something I hadn't prepared for and isn't something you can train for happening, so in my opinion bring something of your own and extra as you never know how you'll feel that day and don't want to be stuck waiting for the on course gu.
I don't like to carry a lot either but do wear a belt and have pockets in my skort shorts I use.
Oh And carry in a secure spot, right at the start so many gu packets were falling out of people's belts ahead of me, I kept hearing and seeing them, thinking back I should have picked them up, hahaha, but may have been trampled on at the get go.