Welcoming Back the Carbs, Carefully

For years, consumers have hopped on the low-carb bandwagon, but they may soon hop off. The pendulum has swung back in favor of grains, thanks to new research that shows whole grains can lower the risk of heart disease and some cancers.

Hundreds of products touting the benefits of whole grains have popped up on supermarket shelves -- you'll find whole-grain Chips Ahoy cookies, whole-grain Goldfish crackers and even whole-grain white bread.

But how do you know which products are best for you? The Food and Drug Administration has issued preliminary guidelines on whole-grain food labels, but for now nothing's changed on your grocery shelves, and experts warn not all products that appear to have whole grain nutrition are what they're cracked up to be.

The 'Whole' Story

Whole grains never got much attention until the government flipped the food pyramid on its head last year, recommending more whole grains in your diet, such as whole wheat flour, oatmeal and brown rice.

For a processed food to claim "whole grain" on its label, it must include every part of the grain, which is harder to manufacture and harder to keep fresh on supermarket shelves.

"All the products that say they contain whole grains do, but they contain just widely varying amounts of whole grain," said Dr. David Katz, a nutrition professor at Yale University and an ABC News medical consultant. "The overall nutritional profile ranges from … good to bad to ugly."

He said one way consumers may get confused is by focusing on healthy-sounding words like oat nut, cracked wheat or 12 grain, which sound good but are usually not whole-grain products.

To decode the labels, Katz said look for the fiber. Fiber provides much of the health benefits of whole grains, so a serving should contain at least two grams of fiber per 100 calories.

Supermarket Test

"20/20" decided to put three smart, suburban New York professionals to the test to see how much whole grain would end up in their grocery carts when asked to shop for healthy foods.

They were given a shopping list with a variety of food categories, including bread, beverages and crackers, and were old they had 10 minutes to shop.

While none of our shoppers knew the subject of our story, all three came back with plenty of products advertising whole grains. Katz then checked their carts and critiqued their choices.

"We've got Nutri-Grain cereal bars … the name alone sounds like that's something that should be pretty good for you. Interestingly, in 140 calories, there's less than one gram of fiber," said Katz. "That tells me that whatever grain is in here … [you're] not getting too much whole grain."

Shoppers also chose oatmeal bread with whole-grain oats, but Katz said don't be fooled. Even brown-colored bread that looks healthy, may not have whole grains, as the appearance is not always an indication of the nutritional value.

Reasonable Advertising or Marketing Ploy?

During our test with New York City food shoppers, several of our participants chose General Mills cereals, including Kix, because the boxes advertised whole grains.

Last year General Mills became the first leading food manufacturer to emblazon all of its cereals with the whole-grain banner. That included Cheerios and Wheaties, along with sweeter cereals like Cocoa Puffs and Lucky Charms, which have more sugar than whole grains.

"We responsibly added the whole grain to our cereals at a minimum of half a serving," said nutritionist Susan Crockett, director of the Bell Institute at General Mills.

Many of the dozen nutritionists we consulted for this story applauded the campaign and called it a step in the right direction. But some of those same experts also said the nutritional benefits of the whole grains in cereals like Trix are undercut by a load of sugar.

Crockett, the General Mills nutritionist, said the brand's labeling is not misleading because the cereal does contain half a serving of whole grain, as defined by the government.

"We feel that we advertised and communicated with consumers in a clear, responsible and nonmisleading way. We stepped up to this project with total integrity," said Crockett. "We feel fine about the banner of whole grain on our presweetened cereals. It is truthful and non-misleading."

Katz has a different opinion: "This is candy basically, and yeah, there's a little bit of whole grain in here, but there's a lot of whole-grain lettering on the front of the package."

Tips for Finding the Whole Grains

So how can General Mills get away with marketing whole grains in a sugar cereal the same way it does a healthy one?

The new FDA guidelines only suggest that food manufacturers tell you the amount of whole grains you're getting. Until those recommendations are approved, cutting through the confusion takes a lot of work.

When you're shopping, Katz recommends that you look for the word "whole" in the first spot on the ingredient list. "The ingredients on food products are listed in order of abundance," he said.

He also said it's critical that you look for whole-wheat flour.

"The difference between wheat flour and whole-wheat flour is like the difference between an airplane with and without wings. You know a whole airplane's a whole lot better," said Katz.

And, he said, check out the amount of fiber on the facts panel.

"If you don't see two or more grams of fiber per 100 calories … whatever it says on the front about whole grain you can forget about it. It's just a token," said Katz.

In the end, no matter what you're buying, you should check the fine print. It's still the best place to find the whole-grain truth.