Navigating the freezer aisles can be frustrating. Those convenience products may be high in price, processing, and calories.

Not all frozen foods are created equal, says Cynthia Sass, MPH, RD, author of the New York Times best seller S.A.S.S! Yourself Slim: Conquer Cravings, Drop Pounds and Lose Inches. This doesn't mean you can't use frozen foods. It just means that you'll need to become an educated shopper.

Sass offers the following strategic tips to help you narrow in on the healthiest frozen food choices.

1. Check the ingredient list.

"My rule is that the ingredient list should read like a recipe you could recreate yourself," Sass says. "If the ingredients sound like a science experiment and include anything you don't recognize or couldn't purchase in a farmer's market or your local food market, it's probably not worth the shortcut."

2. Pay attention to serving size.

Some frozen foods contain more than one serving size. Read the label to find out what you're eating and the calories it contains, so you can determine how the food best fits into your overall daily meal plan.

3. Check the sodium content.

Most foods naturally contain sodium, and some also have added salt or sodium. While some sodium is okay, you need to be aware of how much you consume each day. "Think of it as a budget. Most of us should limit our sodium intake to 1500-2300 mg per day," Sass says. "Look at the mg of sodium per serving, multiply if you're going to consume more than one serving, and compare that to the daily cap."

4. Opt for frozen vegetables.

Hands down, these can be a healthy, versatile choice to go with a meal—provided they don't have any added ingredients besides the vegetable(s). Sass recommends steaming the veggies and then adding some healthy seasonings. For instance, broccoli with sundried tomato pesto; French cut green beans with olive tapenade; and spinach with roasted red pepper pesto. (One tablespoon of pesto/tapenade is needed per one cup of vegetables.) "I also use frozen vegetables in stir frys, sautéed with a combination of brown rice vinegar, fresh squeezed orange or tangerine juice, minced garlic, fresh grated ginger, and crushed red pepper," she adds.

5. Make batches of homemade soup—for now and later.

Save time in the kitchen without sacrificing taste or nutrition by making a big batch of soup or chili and freezing some for later. Sass suggests using low-sodium broth, loading up the veggies and including small portions of whole grain barley or rice for a healthy and easy-to-make meal. Just defrost, reheat, and serve.

6. Freeze your own fruits.

Sass says that berries, sliced bananas, mango, and pineapple all freeze well. When they're in season and you have leftovers, place them in a single layer on a cookie sheet so they aren't touching. Freeze for 30 minutes; remove; then transfer to freezer bags. Remove as much of the air as possible (some people suck it out with a straw), seal, and label. Sass suggests using the frozen fruit for smoothies or munching on them right out of the freezer.

For more easy and healthy meal ideas, check out Sass's book on Amazon.

Cynthia Sass, MPH, RD, reviewed this article.