Apr. 7, 2008 -- The "Nutrition Facts" panels on foods may not be as accurate as you might think.
"Good Morning America" hired a lab to test a dozen packaged food products to see if the nutrients in them matched the labels.
"I don't think anyone knows for sure how accurate the nutrition labels are," said Delia Hammock from the Good Housekeeping Institute.
First the good news: three product labels were off, but in a healthy way. Weight Watchers Blueberry Muffins contained even less fat than listed. Nabisco Mini-Oreos and Pepperidge Farm Chocolate Chunk Cookies had more protein.
The government actually allows foods to contain 20 percent more diet-damaging nutrients than the label lists before taking enforcement action.
All 12 of our products, were, indeed, over for at least one nutrient. Three of those were over by more than 20 percent, including David's Sunflower Seeds with 23 percent more saturated fat, Ritz Crackers with 36 percent more sodium and Wonderbread with 70 percent more total fat.
"If you're getting 20 percent more saturated fat or sodium in foods routinely, that's a major problem," said Michael Jacobson, from the Center for Science in the Public Interest
In another case of government doublespeak, "no" means none, but that's not necessarily what "zero" means. Manufacturers are allowed to list "0" even if their product contains up to half a gram of a nutrient.
"So, to know these fine distinctions, you really have to read the rule book," explained Jacobson.
Despite the "0" on the labels, we found small amounts of saturated fat in Baked Lay's Potato Chips, Rold Gold pretzels, Special K Cereal and Grape Nuts Trail Mix Crunch.
The government says trans fats are downright dangerous. The Nabisco Cheese Nips label boasts "0" trans fat but, according to our test, each serving actually contains about a quarter of a gram of the artery-clogging fat. It's perfectly legal, but also troubling because the Food and Drug Administration says Americans should try to eliminate trans fat from their diets.
As for total fat, consider Snackwell's Devil's Food Cookies. With "0" fat listed, they're supposed to be a guilt-free treat for dieters, but the lab we hired found more than a quarter of a gram of fat in each one-cookie serving.
"Unfortunately Americans don't eat just the serving size on the label. Very often they eat maybe two, three, even four times as much," said Hammock.
"Good Morning America's" study was small and only one sample of each product was tested. When the FDA tests it buys multiple samples from different lots.
Wonder Bread pointed this out in their response to the "GMA" test, calling the results "questionable" and saying "it is possible that a sample from one part of a loaf could have a slightly different fat content from another slice…" but that either way "Wonder bread is a low-fat food."
Ritz Crackers also said the FDA method is more accurate and fair and added that the specific box we tested came from a lot that "had undergone checks for compliance" and met "production specifications."
David's Sunflower Seeds said: "no two sunflower seeds are alike. Weather, size of the seeds and many other factors are dictated by mother nature, and our labels reflect the average."