Back when I was in the US like 5 years ago, I've been able to stretch my meals out to about $40 per month.

You can make a flavourful cheesy-pasta (not actual mac-and-cheese) with some pasta, some chicken bouillon, a tablespoon of butter or margarine, and a slice of processed cheese. For protein you can buy cheap chicken franks and chop it up, and for veggies I like frozen peas and frozen broccoli. Get store-brand for the cheapest possible options.

I was so stingy that I was able to stretch one box of pasta out to 11 meals, and I still looked forward to each meal.

To keep myself from going insane, every grocery run (every three weeks) I rewarded myself with a gallon bucket of store-brand ice-cream and two packs of store-brand chocolate sandwich cookies, all of which I completely devoured within one week.

I lost hella weight and felt really good about it. Unfortunately, I've gained it all back now.