For keeping large amounts of easily-made energy reserves (i.e. food) with you, Sammiches would seem like a decent investment. Once you get high enough in Animal Kinship you can make a Sammich (worth 29E) for only ~7 spent energy. A net win of 22E for just a bit of cooking work. However, since Sammiches can only fit 20 in a slot, the net consumable energy for a fully-stocked slot of Sammiches is 580—which is 20 less than if you just filled it up with Meat.
First of all, this seems like a (minor) game balancing flaw, where effort spent in crafts actually reduces the overall value of that which you spent the effort on. One can argue, “but you get Experience from it too, which you aren't counting here” but two counter-points to that: 1) you’re also consuming 5 grains per Sammich, which if consumed raw equal 5 energy, and 2) Experience should be a bonus gain that you get for performing actions, rather than merely consuming raw foods. So I’m curious whether this 580/600 Energy disparity is an intentional and conscious decision by Tiny Speck, or if it is an oversight in game balancing maths.
Now to the titular question: does anyone know what the most efficient energy-per-slot item is? The Sammich is slightly lower than raw Meat, as explained above, but I wonder if anyone knows the item that stores the most consumable energy per backpack slot. Let's hear your thoughts (and do some crowd-sourced maths)!