Personally, my wife and I spend on average $80 every two weeks on groceries. Here's most of what we eat:
We eat fruits and vegetables, but not as the 'only' thing we eat. We also eat sandwiches (pre-packaged meats are cheaper, and we love the portion control of the little individual sandwich packs, generic only), pasta, rice, chicken, ground turkey instead of ground beef (better for you AND cheaper), cereals for breakfast like shredded wheat, eggs, stir fry using frozen vegetables and chicken, etc.
Some tricks are to REALLY shop. Buy generic pretty much whenever you can, buy frozen foods, frozen veggies, lots of spices, watch out for 'expensive' categories like cheese, beef, and deli lunch meat. Spend more of your money on the staples that you need, and then add things in when you have the budget. Oh, and set a budget and stick to it. Again, we have $80 every two weeks.
For snacks, make your own granola bars! I know, this is weird, but get some granola from the store, and make bars by putting just enough honey in it to keep it's shape. This is good for you, not nearly as expensive as just buying them, and... kinda fun. Once you have the shape you can bake them in the oven to make them a little harder, and voila! Good luck!