On Nutrition by Ed Blonz

Why Do Serving Sizes Vary?

DEAR DR. BLONZ: What is the difference between a “serving,” as used on the USDA food pyramid, and the “serving size” on food labels? Why is there a difference? -- J.L., San Leandro, California

DEAR J.L.: It can get confusing if you don’t get the distinction. The serving sizes on the food pyramid are consistent with dietary recommendations, while food packages have the burden of dealing with the size of the container and providing correct nutrition information for the amount to be consumed.

Let’s use vegetable juice as an instructive example. According to dietary recommendations and the USDA Pyramid, one serving is 8 ounces. In the store, however, vegetable juices are often sold in 12-ounce cans, where the Nutrition Facts panel indicates that the serving size is the entire can.

The purpose of the Nutrition Facts label is to inform the consumer how many calories, grams of fat, sugar and protein, etc. are present in the portion they are most likely to consume. If the 12-ounce can had a serving size of 8 ounces, there would be 1 1/2 servings per container. Then, having the whole can, as individuals tend to do, would require math to get an accurate count of the nutritional contents. To extend this example, check the label of a large bottle of the same vegetable juice. On that large container, the Nutrition Facts reverts to the 8-ounce standard.

It makes sense when you consider that the priority with the Nutrition Facts label is to tell consumers what’s in the foods, allowing them to compare brands and options.

Before recent upgrades, the Nutrition Facts labels’ serving sizes were consistent with USDA recommendations. But this caused confusion when a small bag of chips, for example, would contain more than one serving. Health professionals voiced concern because it made the calorie/fat numbers on the container out of sync with the amount consumed.

So while food label serving sizes often differ from the USDA recommendations, they now provide information about the amount that people actually eat. This approach is now required, and can facilitate comparisons between brands.

For reference, here are some serving sizes used with dietary recommendations.

-- Vegetables: 1 cup of raw leafy greens, 1/2 cup of cooked or chopped vegetables

-- Breads, cereals and grains: one slice of bread; 1 cup dry cereal; 1/2 cup cooked cereal, rice or pasta

-- Fruits: a medium apple, orange or equivalent-sized fruit; 1/4 melon or grapefruit; 1/4 cup dried fruit; 1 cup berries

-- Dairy: 1 cup of milk or yogurt, 1 1/2 ounces natural cheese, 2 ounces processed cheese

-- Fats and oils: 1 teaspoon of oil or a spreadable fat, 1 tablespoon of an oil-based dressing

-- Meat, poultry and fish: 3 ounces, about the size of a pack of playing cards

-- Other proteins: 1/2 cup cooked beans, 4 ounces tofu, 1 ounce nuts, 1 egg

-- Wine/alcohol: 4 ounces of wine, 12 ounces of beer, 1 ounce (a shot) of hard liquor

Send questions to: “On Nutrition,” Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.