I made my own onigiri (rice balls) for a race and plan to do so again. It weighs a bit more than some other options, but digests fast and easy. The taste is inoffensive and I find I’m always in the mood for rice. Whereas there’s only so many gummy bears and Oreos one can eat in a day.
Cooked jasmine rice is about 1 calorie per gram. For comparison, raw sugar is 4 calories per gram and honey is 3 calories per gram. A Stroopwafel is 4.2 calories per gram. Gummy bears are 4 cal/g. Oreos are 4.7 cal/g.