It’s already been said but more fat. Butter, tallow, coconut oil, olive oil, lard, maybe avocado oil

I’ve started making pemmican for food on the go/energy bars.

It’s basically just ground up dried lean beef mixed with rendered tallow. I also add salt, dried fruit that I grind, and ground nuts like pecans & almonds.

Press the mix in a dish overnight then cut it up to individual portions the following day.

Highest calorie food I’ve found