One dollar and fifty cents per day could make a difference for your health. That's the difference in cost between a healthy diet of whole foods and an unhealthy diet of processed foods, according to a meta-study by Harvard University.

“For 60 percent to 70 percent of Americans, $1.50 a day is not a big deal,” the study's author, Dariush Mozaffarian, told Harvard Magazine. However, the figure adds up to $2,200 per year for a family of four, which could be out of reach for low-income families.

Meal planning and grocery-shopping strategies can shrink a family's overall grocery bill regardless of income, according to money-saving experts. And putting together inexpensive meals with healthy ingredients might be easier than consumers think. Three important steps to cutting a family's grocery bill are paying attention to sale prices, planning menus in advance and buying whole rather than processed foods.

It's important to define what a healthy diet means, if a family is trying to keep down costs. It doesn't necessarily mean buying specialty foods, like organic grass-fed beef for $10-$20 a pound or organic quinoa for $5-$8 per pound.

"There’s a misperception about what it means to eat healthier," said nutritionist and food writer Keri-Ann Jennings. "One of the biggest things that I think gets confusing is that people equate healthy eating with specialty items."

Mozaffarian defines a healthy diet as one that reduces "things we know are unhealthy like processed meats, highly refined starches, sugars … trans fat, and sodium,” and that emphasizes "things we know are good like fruits, vegetables, nuts, vegetable oils, and fish." Other foods, like chicken, eggs, whole grains and legumes are also part of a healthy diet.

Buy what’s on sale

One thing grocery-shopping experts agree on is looking at store ads before deciding what to eat for the week. Erin Chase, cookbook author and creator of the website $5 Dinners, recommends looking at ads for meat first since meat is usually the most expensive food item in the grocery cart.

Store sales are cyclical, Chase says. If chicken breasts are on sale, she will buy one package to use that week, and two or three more packages to keep in the freezer, so she won’t have to buy chicken until it goes on sale again.

Steve and Annette Economides, known as “America’s Cheapest Family,” also stock up on sale items. The Economideses like to go to stores that offer price matching, which saves time by getting all the local sale prices in one place. Cutting out trips to the store is one of the easiest ways to save money, according to Annette Economides.

Chase and the Economides family agree that the grocery shopping “sweet spot” is having a fully stocked freezer and pantry, planning menus based on ingredients you have on hand and going to the store to add to your stockpile as items go on sale.

“Instead of shopping at the store, you’re shopping in your pantry and freezer, with everything you’ve already bought at rock-bottom price,” Chase said. It might take a while to get the point where you don’t have to buy items at full price, but that’s the goal.

Plan menus

The Economideses recommend making lists of dishes you can prepare with common ingredients and using those lists to plan menus before going grocery shopping. They make lists of chicken dishes, beef dishes, vegetarian dishes and so on, so they will know what to do with the ingredients they find on sale. They also keep menus simple to reduce costs.

“We’re not gourmet cooks around here,” Annette Economides said. “But people love to come to our house for dinner, because it’s tasty, it’s not always the same thing and we have fun at the table.”

Chase offers menu plans on her website, but she says planning your own menus is easy if you remember that a basic, healthy meal usually consists of a protein, a starch and one or two vegetables.

Whole, not processed

Kerri-Ann Jennings, a food writer and nutritionist, points out that plant-based and unprocessed foods are the healthiest and cheapest meal ingredients. “When you go for whole foods that haven’t been processed yet by someone else, and you process them in your own kitchen through cooking, that is going to save you money and also be the most nutritious,” she said.

Jennings recommends whole grains that have not been processed into things like bread and crackers as a basis for healthy meals and snacks. The bulk bins at grocery stores are a good source for inexpensive whole grains. Beans are another cheap staple food that Jennings and Chase both recommend. Adding beans to meat dishes reduces cost while adding fiber and vitamins.

To save money on produce, all the experts recommend buying seasonal fruits and vegetables on sale.

Produce that is sold by the bag is usually cheaper than produce sold by the pound, Steve Economides said. The bags are not exactly the same weight — for example a 1-pound bag of carrots could weigh as much as 1¼ pounds — so weigh the bags to find one of the heavy ones.

The same holds true for fruits and vegetables sold by the item, for example a head of lettuce that is 99 cents. Some of the heads of lettuce will be heavier than others, so find a heavy one to get more for your money.

Jennings says that frozen vegetables are often cheaper than fresh, and just as nutritious. Canned fruits and vegetables are also healthy, especially the low sodium varieties. She stocks up on frozen fruits and vegetables when they are on sale.

Jennings says often her clients forget that most stores display the price per serving, per ounce, or per pound, so you can compare different brands and package sizes. “The store has done the math for you,” she said.

Have a treat

For some families snacks and junk food are a significant portion of the grocery bill, and cutting down on these purchases can be a great benefit. But families don’t need to deprive themselves completely — just buy treats that are on sale, and make them a once-in-a-while, rather than a daily, indulgence.

Jennings has a great list of healthy snacks on her website. One thing she loves as a snack is popcorn. “People don’t realize that popcorn is a whole grain,” she says.

Jennings suggests making your own microwave popcorn — a cheaper and healthier alternative to processed microwave popcorn, which contains trans fats and artificial flavors. Put a couple of tablespoons of popcorn kernels in a brown paper bag, then fold over the top a few times. You may want to toss the popcorn kernels in a small amount of oil first. Cook this as you would pre-packaged microwave popcorn, for about 2 minutes. Jennings likes to flavor her popcorn with a drizzle of olive oil and some Parmesan cheese, or with chili seasoning.

Homemade hummus or bean dip with raw vegetable dippers is another healthy, inexpensive snack, Jennings says. The basic concept is to process beans with a little oil and salt in the blender, and then flavor the mixture any way you like. Classic hummus is made with chickpeas and olive oil, and flavored with lemon juice, parsley, cumin and cayenne.

Jennings also likes healthy snacks using frozen fruit. She makes smoothies using frozen berries, half a banana, milk, and a couple of tablespoons of rolled oats for fiber and body. Jennings also likes to combine frozen berries that have been thawed in the microwave with plain yogurt, and top this with honey and toasted buckwheat.

All these healthy ingredients can be found in most grocery stores, and strategic grocery shopping is the "fastest way to save money in your family’s budget,” Annette Economides said. "The more you plan, the more you save."