Fooducate Blog - Nutrition Confusion: What is the Percent Daily Value?

Nutrition Confusion: What is the Percent Daily Value?

Posted: 10 Aug 2012 05:12 AM PDT

% daily value

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This is a guest blog post by Richard Perlmutter, MS

One of the most significant sources of information on the Nutrition Facts panel of packaged foods and beverages is the % Daily Value (%DV). It provides context to nutrient amounts. Knowing that a serving of a food contains 600 milligrams of sodium is meaningless to most people. But when that amount is also expressed as 25% of the Daily Value, the significance becomes much more apparent.

The 100% Daily Value amount has several meanings, depending on the nutrient it is associated with. Also, how the 100% Daily Value amount is determined is an extremely important and controversial topic within the nutrition community.

Public health officials have divided the Nutrition Facts nutrients into three categories–Nutrients to encourage, Nutrients to limit, and Nutrients without comment. With each, the %DV has a unique significance.

Surprisingly, the Nutrition Facts panel makes no mention of the three categories of nutrients. One must refer to supporting material provided by the federal Food and Drug Administration to learn about these categories and the differing interpretations of 100% DV.

Nutrients to encourage: These are Dietary Fiber, Vitamins A and C, and the minerals Calcium and Iron. There are also others. But unlike these five, they are not required in Nutrition Facts. They are listed on a voluntary basis.

In general, the American public does not get enough of the nutrients to encourage. The 100% Daily Value is more than what most people consume. The 100% Daily Value amount is a goal, an encouragement to increase the intake of each of these nutrients.

Of the nutrients to encourage, dietary fiber is the only one that has an amount posted in Nutrition Facts. The others only list a % Daily Value.
There are 7 g of fiber in a serving of Post Grape Nuts brand breakfast cereal. The 7 g are 28% of the Daily Value. This percentage is based on Dietary Fiber having a 100% Daily Value (the amount we are encouraged to consume) of 25 grams. Americans typically consume only 15 grams.

Nutrients to limit: These are Total Fat, Saturated Fat, Trans Fat, Cholesterol, and Sodium. For these nutrients the100% DV is an approximate upper limit of safe consumption. However it is better to have less. Because trans fat has zero nutritional desirability, no %DV is assigned to it.

As you can guess, all of these nutrients to limit were chosen because of associations with cardiovascular disease. However, newer research questions the relevance of two, and possibly three, of these dietary risk factors.

Cholesterol in food has been downgraded as a cause of heart disease. That is why eggs have been rehabilitated as a desirable food. This change has not caused cholesterol to be deleted from the Nutrition Facts panel. Nor has the deletion been proposed. The 100% Daily Value for cholesterol is 300 mg. Americans consume a bit less–about 280 mg a day.

Similarly, prominent researchers believe that total fat consumption is unrelated to cardiovascular disease. Again, no proposal recommends the deletion of this nutrient from the Nutrition Facts panel.

Some also think that saturated fat is innocent. But this sentiment lacks widespread support.

Nutrients without comment: There are three–Total Carbohydrate, Sugars, and Protein. The 100% DV is always shown for Total Carbohydrate and occasionally shown for Protein. There is no %DV for Sugars.

Within reason, consuming more or less carbohydrate or protein is not regarded as a health concern for most people.

With the heightened awareness of obesity, consumption of added sugars in processed foods and beverages is a public health concern. A 100% Daily Value for added sugars–which excludes the natural sugars in fruits, dairy foods, and some vegetables–is being considered for inclusion in Nutrition Facts.

WHAT SHOULD THE 100% DAILY VALUE BE?

The Recommended Daily Allowance (RDA) of iron for women of child bearing age is 18 milligrams. For men the RDA is 8 milligrams. Often breakfast cereal is fortified with iron at 50% Daily Value. What amount is used?

Nine grams is used, because the 100% DV is based on the need of women of child bearing age. But 9 g is more than what men need.

This example illustrates a major controversy. Currently the 100% Daily Values are chosen by what is designated as a population coverage approach.

In most cases the highest level needed by any demographic group is set as the 100% DV. The danger is that other groups, which require less, may be consuming too much.

A desirable alternative is to base the 100% DV on what is known as the population weighted Estimated Average Requirement.

The amount of a nutrient that satisfied the requirement of 50% of the American public, age 4 and above, is the population weighted Estimated Average Requirement (EAR) for that nutrient.

Switching from population coverage to the population weighted EAR is currently being considered by the federal government. The greatest opposition to this change is coming from the nutritional supplement industry. Demand for its products would diminish with the EAR approach.
What appears to be simple often isn't, as this discussion of % Daily Value shows.

Richard Perlmutter is the owner of Abington Nutrition Services LLC which prepares nutrition labeling for products manufactured by food and beverage companies. He also takes an interest in seeing that government nutrition policy is in line with nutritional science.