Depending on your diet there are cheap healthy options for everyone. Whether it's a low sugar, low-carb, low-fat, organic, diabetic, or just an overall healthy diet the options are there for you!
A couple things to remember:
Prepare and stay organized! Using your coupons from newspaper inserts, the internet, or catalina's (coupons that print out from the store) along with store circulars or deals can help to cut down on those costs.
Regular food items aren't the only one's with deals...many food items that have regular and low fat/sugar/cal/etc, often have deals for many of the different varieties...sometimes it's only the low-fat sliced cheese that is on sale for the sliced cheeses or the turkey bacon instead of regular bacon that is on sale
So here is a list of some foods that i've caught onto that tend to be cheaper (and that's before they even go on sale!!)
Bagged Rice--> this is something that buying in bulk is a huge money saver. Rice has an extremely long shelf life. I don't want to give an exact price b/c it varies depending on where you shop. Look for brown rice, it is loaded with the right kind of carbs. It also has fiber and protein to help keep us full with a well functioning digestive system. Can be used in so many meals from stir- fry to chili to side dishes. Rice isn't going to fair so well on a low carb or low calorie diet, but it is fairly easy to make and low in fat and no cholesterol
Tuna--> Canned Tuna is a great deal because it is great for a lot of diets, fast to make and of course cheap!! There are often cans of tuna for under $1 a can. Tuna can be made with mayo, carrots, and dijon mustard and put on a salad or a sandwich or even eaten by itself. Tuna is great for a low carb-high protein diet and is also low in fat and calories. Make sure to buy the tuna in water, not oil!
Beans--> You can buy beans in cans or in a bag. They are a great example of food that is pretty cheap on it's own and often goes on sale. A common theme so far has been a long shelf life and beans are no different! So load up on this deal during those stock up sales! Beans are also a versatile food that can be used in salads or chilies. They are loaded with fiber and protein to keep you fuller longer. However, it is a bit high in carbs and calories.
Pasta--> Stick to the whole-grain, that's what will be best for fiber and protein. Pasta also is a food to hold out for and buy during stock ups. It can often be found for $1 for a box (8 servings) and lasts for quite a while. Imagine how much you can save when you combine the stock up deals with your coupons?!?!?!? Pasta is also just such a flexible food. It tastes great with seafood, meats, cheeses, sauces or just butter. Super easy for the lazy or lacking creativity eater. Just be careful, b/c its way to easy to eat a lot of it and it's loaded with carbs and cals.
Yogurt-->Greek yogurt seems to be all the craze now and rightfully so it's thick, yet creamy, filling yet relatively low in calories. However, unless you are couponing and happen to stumble upon a good deal along with it, it will be a bit pricier than some other yogurts. The best greek yogurt deals i've seen end up being right around $1 or a little bit less for one 6oz container of greek yogurt. However, regular yogurt can also be good for you, and even better for your wallet! I'm guessing that because greek yogurt is taking off, other types need to compete, and not better way to compete than lower prices. I've found deals that are like 10 yoplait yogurts for like $6. Doing the math makes it almost $.50/container + whatever coupons deals you have could make it even cheaper. Yogurts can be combined with fruits for smoothies, or with honey, chocolate chips, even cereal (if you're that courageous). It is a good source of protein and calcium. A bit high in the carbs and sugar category, but that also depends on whether you buy plain or one's with fruit on the bottom.
Eggs--> A lot of protein and no carbs/sugars. It's great for a quick and easy breakfast or in a meatball recipe. Eggs are also a food that goes on sale pretty frequently in some way shape or form; it maybe actual eggs in a carton or egg substitute.
Bread-->there are all different kinds of bread that are a good deal. Whole grain slices, wraps, bagels, english muffins and probably a few others that i'm missing. Look for the whole grain slices for more fiber and protein. There are some breads that tend to be pretty cheap and often go on sale (BOGO, buy one, get one 50% off). Believe it or not, bread is a great stock up item. Bread can be put in the freezer to preserve it much longer. I like to throw it in the fridge the night before and it's de-thawed.
Cheese-->Sorry, but not all cheeses are the same. Some can be pretty pricey. However, there are some that aren't going to break the bank and can be used in so many foods. Look for the cheapest brands from shredded, to sliced, to string cheese, there is usually a deal out there that is even cheaper. Often the low fat cheeses are on sale too and finding coupons aren't to difficult either.
Fruits and veggies-->frozen fruits/veggies are often cheaper than fresh. You can find bags that are 10/$10 and they are easy to de-thaw/stem. However for those foods that don't come in the frozen foods section or you just want fresh fruit/veggies, wait for them to be in season, that's when you'll find the best deals. Currently, I can buy Avocados/Mangos 10/$10...not to shabby. Or if you have the time and are in to it...grow your own!
Frozen fish/seafood--> Salmon/scallops=a bit on the expensive side, frozen shrimp/tilapia=much cheaper. If you are sick of tuna/eggs and on a high protein low carb diet, these frozen foods can be relatively cheap and you can still feel like you are having an expensive dinner without actually spending a lot of money.
for more cheap and healthy foods check out: http://www.webmd.com/food-recipes/features/cheap-healthy-15-nutritious-foods-about-2-dollars?page=4
Tuna melt (entire meal could easily be made for about $1)
-2 slices of whole grain bread
-one can tuna (in water) drained
-2 slices of cheddar cheese
directions: combine tuna, carrots, celery, mustard and mayo in a bowl. Put 1 slice of cheese on each piece of bread, then put the tuna on one side of the bread, then the slice of tomato and the other piece of bread and cheese on top. Heat up a skillet (medium heat) and put the sandwich on, flipping after about a minute or 2.