These new rules of nutrition will change the way you buy food.

By Bonnie Taub-Dix, RDN

FICTION Buying fresh is always best.

FACT Don't give the cold shoulder to everything else. Produce from the freezer section is often superior, since crops are harvested at the height of freshness and flash frozen to quickly seal in nutrients and flavor. Canned produce has advantages too: Certain nutrients—like the antioxidant lycopene, found in tomatoes—may be more readily absorbed by your body when they come from canned foods.

FICTION Don't eat ingredients you can't pronounce.

FACT Not every word with multiple syllables should trigger a "Beware of harmful ingredients" reaction. Cyanocobalamin, for example, sounds like something you should probably steer clear of, but that's actually the scientific name for vitamin B12. Consider doing a quick Google search before casting an item out of your cart due to a 15-letter word on the label.

FICTION White foods have no value.

FACT While dutifully trying to "eat the rainbow," don't forget that white is a color too. In fact, some white foods (cancer-fighting cauliflower and immune-strengthening garlic) offer substantial quantities of shortfall nutrients—ones we don't get enough of. A medium baked potato, for example, provides more potassium than a banana and offers a healthy serving of fiber, vitamin C and magnesium.

FICTION Only shop the perimeter of the store.

FACT Don't avoid the middle. It's stocked with superfoods like fiber-rich ancient grains (millet, sorghum and quinoa) as well as plant-based protein sources (including chia seeds, flaxseeds and nuts). When it comes to bargains, you can't beat beans, the unsung supermarket heroes whose soluble fiber helps control cholesterol levels. Kidney beans, for example, provide 22 grams of plant protein per 1/2 cup.

FICTION Avoid processed food.

FACT Unless you're following a raw diet, technically almost everything you eat is considered processed. What you should do instead: Focus on avoiding highly or ultra-processed foods (which contain ingredients not normally used when cooking from scratch). These items usually have more sugar, sodium and unhealthy fats than wholesome ingredients.