The Ten second rule- this is the rule that any food that lands on the floor is still edible as long as you retrieve it before 10 seconds have elapsed any longer than this is considered a social faux-pas and is disgusting.
Odd meal combos- if it's still in date then it can be cooked with anything that is still in date. It is still that is considered a balanced meal for example fried eggs, toast, Yorkshire puddings and gravy. Yummy.
Ready meals- If you can pierce it with a fork, microwave it then eat it that is fine. Often these are cheaper than buying separate ingredients.
Stealing your fellow student's food. If you didn't buy it and don't have permission to eat it DON'T! We're all students and we're all as poor as each other.
Eat anything past it's used by date- this just leads to food poisoning. In short just don't do it.
Living off fast food is not a good plan as you will gain weight and end up looking like Fat Monica in Friends and personality can only take you so far in a relationship.
It's my healthiest one and easiest one too.
Take one carrot, some broccoli and some pasta, and some cheese for taste (not advised if lactose intolerant).
Boil the pasta for a few minutes then add the veg, cook until carrots and pasta are soft. Drain the water, place in a bowl, sprinkle cheese on top, then eat.