Honey in a gel flask (holds basically 5 gel packets). What I do is warm the honey so it's liquid (if set at all), get a zester and add some lemon zest or orange zest to the honey, infusing the flavour to the honey. This helps to take some of the harshness off the honey cos it can burn a little if you have it neat. Always have a drink after cos it's hydroscopic and sucks moisture out of you.
It has pretty much the same amount of energy as a gel pack but in a different balence of sugars so it's not all available. I use honey simply because I have approx 600,000 bee's making it for me and that makes it way cheaper for me than buying gels.
Gel Flasks are simply small flexible drink bottles.