FDA, Food Industry Grapple Over Labels : Regulations: The government wants companies to agree to new rules on standard serving sizes.

When you buy a 50-cent bag of pretzels from a vending machine, do you expect it holds 1.65 servings? Do you usually drink half a 12-ounce can of soda and put the rest in the fridge?

Most cereal boxes list 90 to 110 calories per serving, but serving sizes range from one-quarter cup to a cup and a quarter. And just how much tuna should be in one serving?

These are some of the contentious issues federal regulators and the food industry are facing as new food label regulations are worked out.

It’s not enough to compare calories, or fat or sodium. You must also look at serving sizes. But the Food and Drug Administration and the industry say it will be tough to set standard serving sizes, since companies now can set sizes that put their products in the best light.

The goal of the FDA plan is that “if you look at one can of green beans and you compare with another can of green beans, without even looking at the serving size, at least you will have a fair basis of comparison,” said Marilyn Stephenson, part of the team working on label regulations for the FDA’s Office of Nutrition and Food Science.

The FDA decided to standardize serving sizes for 159 categories of foods.

Today, however, “there is no common accepted standard,” said Jeff Nedelman, vice president of the Grocery Manufacturers of America, a Washington-based industry group. “It’s left to the company to determine what a serving size of their products are.”

The National Food Processors Assn., another industry group, wants industry to continue to set serving sizes. The FDA could step in when a company is “using inappropriate serving sizes,” said Allen Matthys, director of technical regulatory affairs for the association.

What he doesn’t want, Matthys said, is “change for the sake of change.”

For example, he said, with most canned fruits and vegetables based on half-cup servings, the FDA originally proposed new sizes that were not much different.

The agency now is working on a second round of proposals, based on comments at public hearings and from Congress, which passed the Nutrition Labeling and Education Act last November. Draft regulations are due this November.

While some labels clearly state nutritional content based on amounts that are easy to count, such as a specific number of cookies, others make the job more difficult.

A 12-ounce can of many diet sodas contains two servings. Many sugared sodas have no nutrition label at all.

Cheerios’ serving size is 1 1/4 cups, while for some bran cereals it’s a quarter cup; others are somewhere in between. Many food labels list serving sizes by ounces, although it’s unlikely most cooks weigh their food.

A 6 1/8-ounce can of Star Kist solid white tuna packed in spring water contains 3.1 servings. Kraft Swiss cheese slices lists a serving size of one ounce, not number of slices. And one juice box of Ocean Spray pink grapefruit juice cocktail contains 1.4 servings, according to the label.

Del Monte, on its 15-ounce box of raisins, lists a three-ounce serving size, while Sun Maid golden raisins are listed in half-cup servings.

Congress has directed the FDA to come up with serving sizes in common household measurements--cups, slices, tablespoons, even ounces--but still leaves open the question of just how much food that serving should contain. Ten potato chips? A cup of cereal?

“It is important because the serving size drives the rest of the nutritional profile,” Nedelman said. “This is a very competitive business, and we want a level playing field so all foods are treated the same.”

The FDA is responsible for most foods, except meat and poultry; those are covered by the U.S. Department of Agriculture. Separate, voluntary labeling is expected for those foods.