Is there any sort of resource to know what stats do what exactly? A lot of stuff is self-explanatory, but some food buff certain stats (Like PA or R+) and I have *no* idea what those are doing for me.
PA and MA would be stuff like Physical Attack and Magical Attack, stuff like MPR and HPR is MP Regen and HP Regen, and the R you're seeing is also regen for the stats (Like AP+1MP+5HP+2R would be AP regen+1, MP regen+5, HP regen+2). Easiest way to know what you're getting from food is by opening the menu and looking at the 5 stats at the bottom, which is listed as:
AP (stamina regen) MP (Magic Regen) HP (Health Regen) W (Weapon Attack) M (Magic Attack), though i never bother much with specific foods as it's barely a difference (AP+1 is about 0.30 seconds from food), i just stockpile on jerky for the overall buff from not being hungry.