Worldbuilding: Food of Runeterra (A Smaller Megapost)
Kestrel's thoughts about exceedingly mundane aspects of Runeterra continue! Once again, I'd love Rioter feedback on my relentless lore harglbargling! Some things are left open ended as we don't know a lot about animals of Runeterra, wild or domesticated. Also, forgive my lack of knowledge about alcohol... Truth be told, I am under legal drinking age in most countries. Edit 1.1 - Added fungi and seaweed. Edit 2.0 - I dug up some food in the lore!
Demacia Animal Products: Red/white meat from game animals/livestock, dairy and eggs from livestock, seafood on the coast/near large lakes Plant Products: Fruit, veggies, grains EDIT: Yes this means a lot of bread Alcohol: Beer, ale, mead, possibly wine Notes: As an agrarian society, Demacia has a pretty damn healthy and balanced diet.
Noxus
Animal Products: Meat and seafood are probably the only locally obtainable foods in Noxus Prime. Some families perhaps raise smaller livestock, like chickens or their Runeterran equivalent, on their own properties in the city. Most Noxian cities (those on the Heirloom at least) are on the coast, so they all share access to varying types of seafood.
Plant Products: Depends on the territory, but for Noxus Prime, any edible plant matter must be imported from elsewhere. There may be some locally grown grain to make things like hardtack for soldiers, but is that feasible?
Alcohol: Anything imported, though it is possible that grapes could grow in even that hostile of a climate. (If my climate guess is correct, which it probably isn't, Noxus has a Mediterranean climate... just like Athens and Napa Valley, aka the Grape Central of two different continents. So provided that holds true... I wouldn't be shocked if wine is one of Noxus' main exports.) Likely all imported.
Notes: Much of Noxus is not a friendly climate for growing your own food. Outlying territories may have separate regional cuisine, e.g. northern Shurima.
EDIT: Manure-fertilized fungi may be a common food in Noxus Prime, though this remains unconfirmed.
Ionia Animal Products: Whatever you're able to commune with Plant Products: See above Alcohol: Sake? I'm clueless here. Notes: Ionia has a spectacular enough variety of wondrous magical food that it's hard to guess exactly what they eat! Some Ionians may be vegetarian (Karma's followers?) though to others' point it is the animals' will to feed you, and not you hunting them down. EDIT: Stuff we know exists: eggfruit (probably just IRL eggplant), river crabs, literal seas of grain, guloo fruit, chocolate, sun apples, spice cherries, cloudfruit, gingerfruit
Bilgewater Animal Products: Any preserved meat they can get their hands on, sea monster flesh Plant Products: Mostly imported stuff if you can afford it. Most probably can't, though the Buhru may import some fruit from the neighboring islands. EDIT: Seaweed? Alcohol: Beer, ale, or whatever you can get really. Notes: Bilgewater has no natural resources whatsoever so this was an easy one.
Serpent Isles Animal Products: Seafood mostly; the islands likely don't have much room for anything that wouldn't be hunted to near extinction, and they definitely don't have room for livestock. Plant Products: Fruit, nuts/seeds (lots of spices?), maybe some root veggies here and there Alcohol: Fruit liquor, possibly mead Notes: Mostly based off climate/terrain (great for vegetation as a whole but not for farming) and lore tidbits on the Bilgewater page. Apparently there are fruit feasts in the isles. I'm jealous. EDIT: stuff we know exists: mango, oranges
Shurima Animal Products: Mostly red/white meat, unless you're near the coast or a large body of water, in which case seafood may be an option. Goat milk does exist. Other types of milk as well as eggs can be inferred. Plant Products: Fruit, nuts/seeds/spices, some root veggies, grains near river deltas (insp: North African cuisine) Alcohol: Beer or other grain alcohol is probably the easiest to guess, though there's also the possibility that there's something like palm sap wine. Notes: Still pretty balanced as long as you're near a body of water. Otherwise it's whatever you can take with you, aside from any wildlife you may find on the sands. Was mainly thinking of North African cuisine for this one.
Freljord Animal Products: Mainly red meat and seafood. Dairy from livestock if that is an option. (Not sure if poultry could handle the cold but larger beasts can.) Plant Products: Grains in the southern/more temperate areas. Presumably not much else unless there are unusually cold-hardy edible plants in the Freljord. Alcohol: beer, ale, mead, etc. Kefir/airag are types of milk-derived alcohol that I think would exist in the Freljord if not elsewhere.
Piltover/Zaun Probably just imported food in general due to an apparent lack of natural resources, though of course the quality differs greatly between the two sub-cities. Synthetic food could also exist, though, creating better nutrition for all. EDIT: Fungi may or may not be a common food in Zaun. EDIT2: There are native berries (cavernberries), possibly edible prey mammals (shadowhares), and a few native bird species (cliff-shrikes, crag-ducks) that may be hunted for food. (Mostly thinking of the ducks here.) Whiskey is present, as is kouaxi, a type of alcoholic drink made of goat milk.
Targon The closest guess I can give for Targonian tribes in the foothills is that they eat like ancient Greeks, who were dealing with similar terrain - grains, legumes, some fruit, animal products exist but are eaten sparingly.