I have heard stories of students needing to reach out and go to food banks in order to get food.
For me, personally, one thing I did in my master's was that I would purchase a large sandwich at lunch and split it—eat half of it for lunch and half of it for dinner—in order to save on food costs for that day. I know that's a small example, but I've definitely seen my friends and fellow students purchasing reduced produce items that are a little less high in quality but will save them money.