I'll add my own five cents.
Do not buy all kinds of "just pour boiling water". All those instant noodles are creepy expensive. A pack of pasta, about half a kilo, will cost several times less than the same half a kilo of Rollton.
If you can order food online, do it. This will allow you to know exactly how much you will have to pay before heading to the checkout. Accordingly, remove unnecessary products.
Try to pay only in cash.
Prepare your own food. If you don't have time, cook on weekends and freeze food. Then you just have to take it out of the maraznik, put it in a microgal for a couple of minutes and the homemade food is ready.
Make yourself a broth. Onion, celery, carrots, pour water over everything, add spices and cook for ten minutes. When ready, remove the vegetables from there, a good vegetable broth will remain. Divide into small portions and freeze. Then it remains to add the roast and pasta and a delicious, nutritious soup is ready.
A small jar of nutella (350 grams), two eggs, a spoonful of flour and baking powder. Mix everything well and send it to the 160-degree oven for half an hour. The result is a brownies - a great cake that will last you a week. At the same time, work for ten minutes and save yourself the need to buy something sweet for tea.
I agree with Zhuravlev - cereals, vegetables for fat, you can fat, fat tail. In our time, there were no such wonderful devices like multicooker and microwave oven - they save time and allow you to diversify your diet
Eating delicious, healthy, satisfying and everything else in one copy is like wanting to lose weight and at the same time eating cakes. But I will give advice on how I ate in my student years and, moreover, gained muscle mass.
I regularly went in for sports, excluded everything harmful in style: flour, sweet, soda and everything like that that is heard. The diet consisted of cereals and pasta, pasta - less often, buckwheat, rice - more often. Buy onions and carrots as a roast (as they usually cost a penny), a little effort and rice with buckwheat + roast becomes the food of the gods. These are carbohydrates. From time to time you can buy proteins for cheap beans: lentils, beans, peas; if you have a little more money, you can cottage cheese, milk.
At first it will not be usual, but then everything will be fine. Muscle mass and high self-esteem in the future are the advantages of all this.