Played this ages ago, when the "multiplayer" aspect just put a bunch of bots into the mix. Admittedly, bots with names and equipment based off of real people, but still bots. Really really stupid bots.
Yeah, food is a constant struggle. And never, EVER pick a service class like an engineer or a chef or something... Every time you use your power, you'll become even hungrier. And the money isn't that great either, because the market is absolutely flooded with fools providing bottom-dollar service and lowering the average rate, trying to get someone to buy from them instead of the hundred other yahoos.
No, there's really only one class to pick. Farmer. Every so often, you'll get free food. The higher your level, the higher level food and more of it. A lot of it is raw, but sometimes you can bring in a nice harvest of crisps. And, as mentioned before, finding a high-level chef for a reasonable price is pretty easy. And farmers are capable of getting rare food that can only be looted from deep in the city. And it's just handed to them for free.
What you don't eat, you can sell. You can get some very nice prices on high-level food, just because it's so hard to get (for anyone who isn't a farmer, that is).
So yeah. Play a farmer. Plug points into critical strike and speed. Get a nice weapon where you can make the most of your crits. Then just farm the early levels for XP so your crop gets more interesting (and more bountiful).
At least, that's the way it used to be.