Richard Merrill is a "want to know." He wanted to know how the Thai pork loin he ate for dinner at the McPherson Grill last Wednesday compared nutritionally to the two lighter fare entrees.

If the recommendations made by the Institute of Medicine, an affiliate of the National Academy of Sciences, came to pass, he would know.

Merrill, a professor of law at the University of Virginia, is chairman of the IOM committee that last week recommended to the government that nutrition information be provided with practically all foods -- including meats, poultry, produce, seafood and even restaurant food. The committee also suggested a new labeling format that would drop the old emphasis on vitamins and minerals and add details on the types of fat and amounts of cholesterol, fiber and sodium.

The committee's recommendations come in the midst of a series of other attempts (by the Food and Drug Administration and Congress) to overhaul the nutrition information on food labels, which many believe has become outdated.

Whatever system finally emerges, consumers will be faced with a new set of numbers and terms. But information can only do so much. By itself, it won't teach people how to use it, nor will it necessarily change the behavior of those who simply don't care.

Laura Sims, dean of the College of Human Ecology at the University of Maryland, and one of 14 members of the IOM committee, agreed that even with new information, many people would be confused. "There's a whole array of numbers. You don't understand the terms, you don't understand the metric system. You say, 'what good is this?' "

In addition, what's good for one person may not be useful for another. Not everyone looks at food labels for the same reasons.

When it comes to using the nutrition and ingredient information, said Sims, there are three kinds of consumers. "Must knows" have food allergies and read labels to avoid certain ingredients. "Need to knows" are on medically prescribed diets and are counting the amount of sodium or cholesterol they consume. And "want to knows," such as Merrill, are nutrition-conscious consumers who use nutrition information to compare foods in the same category. (She didn't mention the "should-want-to-knows" who don't use labels at all.)

Merrill says he doesn't eat by adding up the numbers on food labels, and admitted that he would be surprised if many people did. "The question is how do you provide a label that can be used by a person under a professional dietitian's guidance and not clutter it up too much for the people who need much grosser signals?"

For the people who need less specific signals, the numbers can help denote green, amber and red foods, Merrill said. "Although the members of the committee kept reminding me that it's not that you can never go through a red light, you shouldn't go through it very often." (When the members of the committee -- experts in nutrition science, law and medicine -- met during the course of the last year, Donna Porter and Bob Earl, who edited the report, often provided sustenance with homemade cakes.)

Like many Americans, Merrill, 53, has shifted away from eating a lot of beef, lamb and pork and focused more on poultry, fish and vegetarian dishes. Fresh fruits and vegetables have always been a big part of his diet, he said. His cholesterol is 220 mg/dl, (slightly above the recommended 200 mg/dl), yet he has no other risk factors for heart disease.

Most of the eaten-at-home meals Merrill and his wife prepare are fresh and made from scratch, so packaged or processed foods -- currently the only foods that carry nutrition information, and only 50 percent of them at that -- rarely enter the house. "The only thing we bring home in cans is pet food, which is quite well labeled," said Merrill.

So for the Merrills, nutrition information on fresh foods and restaurant foods would be useful, he said. He would use the data largely for comparative purposes, to help him make trade-offs, added Merrill.

For example, it was the Thai seasoning on the pork loin at the McPherson Grill that tempted him, but he was curious about how it compared nutritionally to two other items on the menu. "Had there been nutrition information, I would have asked about it, but I would have been more likely to ask about it if I had had a big lunch. I had been pretty abstemious during the day."

Or if the menu had included venison, "which I dearly love and I discovered that it had three times the saturated fat as the salmon, which I also like, I might say, 'I'm not going to indulge in that luxury.' But if I had salad for lunch and coffee and fruit for breakfast, I might say, 'I'm going to have what appeals to me most on the menu.' "

Merrill, who presided at the press conference last Wednesday, the day the report was released, had breakfast (bran muffin, fruit salad and coffee) and lunch (mixed green salad with tuna and pink grapefruit juice) at the National Academy of Sciences cafeteria. (At lunch, he put four bread sticks in his suit pocket and forgot to eat them.)

Earl, staff officer for the IOM study, said that standardized serving sizes, recommended by the panel as well as by FDA and Congress, should help consumers make comparisons across the same product category.

"Things will be much clearer once serving sizes are standardized. You won't be wondering what to do with one third of a serving of soup. Who's the one third of the person who gets to eat that?"

In addition, while the IOM panel did not address it, the FDA has proposed that manufacturers voluntarily include "nutrition profiles" on their labels. The profile would show how a serving of their product compares to daily recommendations. For example, 75 grams of fat would be listed as the daily fat maximum, (as part of a 2,350 calorie diet that derives 30 percent of its calories from fat). Then you could get a perspective on that Steak-Umm sandwich steak at 15 grams of fat per serving.

Nevertheless, not everybody consumes 2,350 calories a day. The National Food Processors Association, a trade association that represents processed food manufacturers, has formed a Food Label Education Coalition that will produce educational materials for health professionals to teach consumers how to use the upcoming labels. Education is also a key component of the IOM panel's recommendations.

Regina Hildwine, staff coordinator of the NFPA coalition, said the educational process is very involved. "The simple mechanism of changing something is confusing," she said. For example, distributors and manufacturers of foods from bananas to vegetable oil have been claiming their products contain "no cholesterol." These products never contained any cholesterol to begin with.

Nevertheless, Hildwine said she has heard manufacturers say that when they have taken "no cholesterol" off their labels, that consumers call up and say, 'did you put the cholesterol back in?' "