Often the problem is time.
Grab stuff you can do quickly - cheese sandwhich, soup, apples are fantasic- quick, easy, low calorie and filling. Stock up on fruits - oranges, apples, and my fav snack for studying - grapes.
Microwave popcorn goes a long way too. Use your weekend time to 'cook" something for the week. Some chicken - save some meat for "big meal," some for sandwhiches, some for salads. ) Pre paky salad mixes are great too.) Boil 1/2 dozen eggs. Keep that protein thing going!! Yogurt... um ....a boc of pancake batter is like $2. Add water and you have a heavy meal in 10 minutes.
Lemme do a list istead...
Crackers and cheese
Fruits- apples, oranges, grapes etc
Sandwhich stuff - peanut butter and jelly, meats
Mac and cheese
Spagatti ( can make up before hand)
Salad - regular or add meats, or even just salsa for zing!
"There ain't no vaccine for stupidity* Maxine