I've recently started carrying a bottle full of avocado, olive and MCT oil in my backpack as an efficient store of calories.
OLIVE OIL: https://www.amazon.com/gp/aw/d/B000QWBZQU
AVOCADO OIL: https://www.amazon.com/gp/aw/d/B006K3RCPC
MCT OIL: https://www.amazon.com/gp/aw/d/B00R7FFOLG
GEAR LIST: https://cahlen.org/gear