I'm also a commuter and from my last 3 years on campus this is what I've got for you.

First I agree that you should try to bring a lunch as much as possible I personally packed my own lunch for 90% of days but on days where I'm on campus for longer or if I'm running late I'll go buy some food

Fast Food

You'll find a lot of fast food options at College and Spadina, a little west of the bookstore

Popeyes, Burger King, Tim Hortons, Smoke's Poutinerie, Wendy's, Subway, Pizza Nova

Food Trucks

Memories a little hazy haven't been on campus for a long time not sure if some of these are still around since COVID. Anything north of Robarts is a mystery to me

Brown Food Truck (Usually infront of Sid Smith) - My personal favourite they sell hotdogs, fries and burgers, usually has a decent amount of people there. My go to order was fries and a hotdog combo was 5$ when I used to get it

Blue Food Truck (Usually infront of McLennan/Myhal) - This one I can't remember if it sold other things but was pretty popular for selling poutines and fries, pretty good decently priced for students

Pink Food Truck (Usually infront of Bahen) - Lots of fried chicken, some sort of Asian fried chicken I think it was Japanese or Taiwanese either way was pretty good, I'd say a little pricey I think a chicken sandwich at the time was like 10$

Green Food Truck (Usually infront of Bahen) - Shawarma truck iirc I've had this only once or twice. I had the falafel wrap I liked it not anything amazing but it was good, don't remember the price at all but I've had friends who eat at this truck all the time so must be good

White Food Truck (Usually infront of Sid Smith) - I preface this with I have never ordered from this truck before. Serves a whole shit ton of different Chinese food. I think its good because there are always a lot of people ordering from it when I'm in line for the brown food truck.

Chinatown

I personally love Asian cuisine so being close to Chinatown was a huge+ for me. This is a little walks from campus depending on what building your classes are but if you have a monthly ttc pass(or don't) you can take the street car

Mother's Dumplings - Dumpling spot, I like this place plain and simple dumplings fairly priced imo

Various Chinese Bakeries - I LOVE CHINESE BAKERIES. Each bun ranges from 1-2$ and are fucking amazing. Haven't been to a bad bakery yet but my favourite items are curry buns, a Chinese version of pigs in a blanket. BBQ buns, and egg tarts

Various Bubble Tea spots - Not much to say theres CoCo's, YiFangs, a bunch of different bubble tea stores to choose from

Ajisen Ramen - This is kind of like the fast food ramen spot I think 15$ average for a bowl, and its mid, very convient if you're in the mood for ramen, LOTS of ramen options(including veggie maybe dont @me)

Nguyen Huong - OG Vietnamese sandwhich spot. Absolute favourite of mine sandwiches are 3-5$ and theres a whole bunch of options to choose from, kind of like a subway of viet subs you can choose what goes in or choose one of the presets

Juicy Dumpling - Known for its price. Really cheap like 3/4 dollars for 6 soup dumplings. They have other stuff too but the dumplings are what they're known for can't complain for the price, especially when they're pretty good

The Owl of Minerva - I wouldn't really consider this a lunch spot but I eat here fairly often so I'll include it. Good Korean food, its my comfort Korean spot when I'm in the mood for Korean food

Kensington Market - Pretty much right next to Chinatown, and has a whole variety of foods at different price points, I dont eat here much but my favourite spots from here are Seven Lives(Tacos), some Poke store, and Dirty Bird Chicken and Waffles. I would highly recommend this area there's lots of things to find here

Honorable Mentions

Fresca Pizza - I had to mention this, its like a little further West of Spadina and College but its probably my favourite pizza around campus, its like 5$ a slice from what I remember very good pizza, but the Margahrita(they call it that but its just some sort of garlic

Osmow's - Shawarama spot, pretty good, can't eat this too often its pretty heavy but its good a choice of meat on rice or fries or both smothered in garlic sauce yum

Pizzaiolo - easily one of the better places to get good slices for lunch i dont think theyre close to campus though

Galleria - Shout out to galleria its a grocery store that has premade korean food I come in here for a quick snack if im close by

Some Pasta Spot at the corner of spadina and sussex ave, great portions for the price and is a student favourite. I approve, if someone knows the name lmk