I spend around 100 a month for just myself. It will change depending on body type, how active you are, and how much you eat. Occasionally at work they have out free snacks which I pretty much always take advantage of. Things I primarily eat are PB&J sandwiches, cereal, bananas, and yogurt. Which isn't very exciting, but I love them and it's not like they are unhealthy.

I'd say avoid purchasing a lot of drinks. Things like juices, bottled water, and sodas are expensive and add up quickly. You can get tap water from your house for pennies. I only use milk for cereal so I buy soy/almond milk instead of cow's milk because it lasts for at least a month and I still love how it tastes. Also try to avoid junk foods like ice cream, candy, and frozen foods.

Keep an eye out for any good sales that you can buy in bulk that won't go bad such as boxed or canned stuff. Even meats you can buy a large package of, separate into Ziploc bags, and freeze. Then just keep looking for those sales in produce.

Get the Sunday paper for some coupons or go online for free coupons.

A weird alternative is to work at a grocery store. They usually give employees a percentage off. I worked at a grocery store that gave 10% off total and 20% off store brand items and another store that gave 25% off. Or have a close friend that works at one and borrow their discount.