That's not really a choice. If you don't have money to both investing and food, you shouldn't be investing anything. But to figure out how to eat healthy and cheap, and where to get money from, because at that stage money isn't coming from investing. And you should only invest something you can lose.

If you are in a situation where you choose eating cheaper so that you can still invest, that's a choice. Even then don't compromise by eating unhealthy. Eating well keeps your brain and body in such health that you are able to work more efficiently. Also you will save money when you don't get sick so easily as you would if you ate unhealthy.

It's about priorities. And health should be your priority nr 1.