Our food budget is $70/week for 2 people.

Here are some things I do to keep us healthy and on track $$-wise:

-Plan ahead. I try and make a meal plan for the week, so I only get the things I absolutely need at the grocery store.
-Cook more than you need. I always make us at least 4-6 servings at a time. It's cheaper to cook in bulk and then I freeze some or we just eat it a few times during the week. It means I always have a variety of foods on hand for when I don't want to cook so we don't resort to eating out.
-Don't buy canned beans, buy dry and plan ahead and soak overnight. There's 1/2 to 1/4 the price and have 0 sodium.
-I make our bread etc so it comes out to $1-2 for a loaf rather than $5.
-Buy meat and things you use a lot of on sale and freeze it.
-Check and see if you have an Aldi supermarket near you. High quality food, but because their store is 100% without frills and big ads, you can get your basic things cheap.

for my fiance and me we have a grocery budget between $25-35/wk. It's really tough, but I find coupons, no junk food, look up the deals for the wk. I buy stuff at publix and Aldi's that's on sale. We eat out really cheap 2xs a week on average. which is about 15 extra dollars. But we buy ALL off brand stuff. Find produce on sale. My meat, I buy frozen chicken and lean ground turkey. Also, I've been eating deer from this past season that my family has killed. I get food from the food bank once a month too. I tend to eat a lot of sandwiches. I also make a meat and one to two sides for supper. Breakfast is normally egg whites. Oh, and lunch meat is normally high in sodium and the meat from the deli is expensive but Tyson has sliced chicken (oven roasted and honey bbq flavor) at walmart and it's really cheap and lower in sodium. It's in the lunch meat section. Make sure you eat your left overs as a meal for the next day too

Look at the weekly ads. I usually buy pantry staples like rice, tomato sauce, frozen things, canned vegetables, water in bulk when they have 2 for the price of 1 or things like that. And when it comes to fresh vegetables, meat I go with what is on sale too. Publix is really good with that.
You can buy spices at the dollar store.
Going to the farmer's market gets me to wake up early on a saturday, it's cheap, fresh and local, and I go to the library afterwards which kill two birds with one stone.
Like others said Aldi's awesome.