Secrets From Inside Nutrition Facts Labels

How to use nutrition facts on packaged food for your diet and health.

Medically Reviewed by Kathleen M. Zelman, MPH, RD, LD on October 30, 2008
From the WebMD Archives

The familiar nutrient fact label first appeared on packaged foods in 1986 -- and it has been evolving ever since.

"The original intention was to educate people about the connection between diet and heart disease," explains Irwin Rosenberg, MD, professor of medicine at Tufts University in Boston, who has played a key role in advising the federal government on nutrition labeling.

Information about calories and calories from fat was added as health experts charted the growing problem of overweight and obesity. More recently, several key vitamins and minerals joined the list. Health officials are currently discussing additional changes to the labels.

Using Nutrition Facts Well

All that information can help consumers make healthier choices. But too much of a good thing can also be confusing.

"Translating nutrition facts from the label to the kitchen table can be tricky," says Jonathan L. Blitstein, PhD, a research psychologist at RTI International in Research Triangle Park, N.C., who has studied how consumers use nutrient labels. Jeanne P. Goldberg, PhD, professor of nutrition communication at Tufts University, agrees. "Frankly, I sometimes think people are best served by ignoring most of what's on the nutrient facts panel, and just focusing on a few of the items that really matter."

What should you zero in on? The experts offer some tips to help you use the nutrition facts to boost your health:

Serving Size: A Critical Fact

The top of the label describes a standard serving size and how many servings a package contains -- critical information for interpreting the rest of the numbers on the label.

"A bottle of sweetened ice tea may only have 75 calories per serving. But if that bottle contains two and a half servings and you drink the whole thing, you're consuming 225 calories," says Christine A. Rosenbloom, PhD, RD, professor of nutrition at Georgia State University.

Serving sizes are based on standard measures agreed upon by the USDA and the FDA. One serving of cereal is 3/4 cup, for instance. A single serving of macaroni and cheese is a cup. "Most all of the information that follows on the nutrition label is based on that serving size, from calories to grams of fat. So it's essential to know what a serving is, and to know how much you actually eat," says Rosenbloom.

Saturated Fat and Trans Fat: Key Fat Facts

Fat facts on food labels indicate total fat, saturated fat, and trans fat amounts. Total fat matters if you're trying to lose weight and want to follow a low-fat diet.

"But to prevent heart disease, the crucial items are saturated fat and trans fat," says Myrtle McCulloch, MS, clinical assistant professor of nutritionist at Georgetown University in Washington, D.C. "These are the fats that increase cholesterol levels and risk of heart disease."

Products that contain half a gram or less of trans fats can still claim to be trans-fat-free. To know for sure, look further down on the label to the ingredients list. If the product contains partially hydrogenated oils, it contains at least some trans fats. Look for foods that are low in bothsaturated fats and trans fat.

Daily Values: What Does It Mean?

Along with listing the amount of saturated fat, cholesterol, sodium, and fiber in grams, the label includes "% Daily Value." This item tells you what percentage of the recommended daily nutrient is in a serving.

The daily values are based on a 2,000-calorie a day diet. Men and very active women may need to consume more calories to meet their energy needs. Check the bottom of the nutrition facts box, which includes the recommended amounts in grams for a 2,000-calorie-a-day and a 2,500-calorie-a-day diet.

"But don't get hung up on the math," says McCulloch. "If an item has only 5% or less of the daily value, consider it low in that ingredient. If it has 20% or more, consider it high. A product with 20% or more of the daily value of fiber, for example, represents an excellent source of fiber," according to the USDA.

Fiber: Look for Facts on This Nutrient

Nutritionists say we should consume between 25 and 38 grams of fiber a day. "Most people get barely half that amount," says University of Pennsylvania nutritionist Lisa Hark, PhD, RD, author of Nutrition for Life.

When shopping for breads, grains or breakfast cereals, she suggests choosing brands with at least 3 grams of fiber per serving or more. Fruits, vegetables, beans, and nuts also contribute fiber to your diet.

Sodium: Beware of Too Much Salt

The nutrient label singles out facts on sodium, or salt, for good reason. Too much can increase the risk of hypertension (high blood pressure) -- one of the leading causes of heart disease. Studies show that the lower an individual's salt intake, the lower the risk of developing hypertension. Consuming enough potassium also helps keep blood pressure down.

Look for packaged foods that contain 5% or less of the daily value of sodium. When choosing canned foods, rinsing the liquid off the food can help lower the sodium content.

Sugars: Watch for Empty Calories

Many packaged foods include sugars in a variety of forms, which can add up to a lot of calories and not much nutrition.

"This item on the label is useful because it combines all the different forms of sugar that may appear in food, from refined sugar to honey and fructose," says McCulloch. Remember: 4 to 5 grams of sugar is the equivalent of a level teaspoon of sugar.

Vitamins and Minerals: Useful Facts to Track

The label facts list vitamins A and C, calcium, and iron. If you eat plenty of fruits, vegetables, whole grains, and low-fat dairy products -- or if you take a multivitamin -- you probably don't need to worry about these numbers. If you're trying to get more calcium, look for foods with at least 20% of daily value.

Use Nutrition Labels to Help Set Your Priorities

Because it's easy to feel overwhelmed, determine which information is most important to you. If weight is a problem, total calories are a priority, for example. If not, you don't need to worry about them.

"If you have high blood pressure or a family history of hypertension, zero in on sodium levels," says Goldberg. Be especially alert to the information on nutrition panels when you're shopping for a new item. "That way you can compare a variety of brands and make the best choice for your own requirements," says Goldberg.

Will label reading really make you healthier? Studies show that people who pay attention to nutrition labels do tend to eat lower-fat diets and get more fiber and iron.

Show Sources


Jonathan L. Blitstein, PhD, research psychologist, RTI International, Research Triangle Park, N.C.

Jeanne P. Goldberg, PhD, professor of nutrition communication, Tufts University.

Lisa Hark, PhD, RD, nutritionist, University of Pennsylvania; author, Nutrition for Life.

Myrtle McCulloch, MS, clinical assistant professor of nutrition, Georgetown University, Washington, D.C.

Irwin Rosenberg, MD, professor of medicine, Tufts University.

Christine A. Rosenbloom, PhD. RD, professor of nutrition, Georgia State University.

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