Carly McCready, Courtney Colley and Desiree Broadwater are just 10 years old, but they are getting a head start on living to a ripe old age.

That's because they've learned that nutrition can make a difference. They know it's not good to eat too much fat, because that can lead to clogged arteries and heart disease. They know it's good to get plenty of exercise and it's bad to smoke. And they also know that it's OK to have a hot dog occasionally, because the goal is balance.

"The most important thing I learned is that we should have a balanced diet," says Courtney. "And we shouldn't eat too many fatty foods. It's important to keep our body healthy so it'll run the way it's supposed to."

Carly, Courtney and Desiree, all fifth-graders at Berkshire Elementary School in North Point, are three of the thousand-some participants in the Food Re-education for Elementary School Health Program (FRESH) at the Johns Hopkins Bayview Medical Center (formerly Francis Scott Key Medical Center). The program is designed to find the most effective ways to get nutrition information into a community where preventive medicine just might lower health-care costs.

All of the children in the program are from 10 elementary schools in the area of southeastern Baltimore County around North Point and Dundalk. It's an area where studies have shown a high risk of heart disease.

"We've been dealing for many years with heart problems in adults, many young adults, adults in their 30s and 40s who have children this age," says Kerry J. Stewart, an associate professor of medicine who directs the Heart Health Program for the medical center.

So, a few years ago, "We kind of got excited about the fact that we should attempt to keep these kids healthy and keep them from becoming sick adults."

The area is one of heavy industry, where high-stress jobs, prevalent smoking and lack of information when the adults were young contribute to the fairly high incidence of heart disease, says Dr. Stewart, who is a clinical exercise physiologist.

With the children, Dr. Stewart says, "Our focus is really to change their habits, and change their attitudes, and change their knowledge in the short term, hoping that that will have a long-term carry-over effect. By developing good habits young, they can avoid many of the health problems."

The results so far have been impressive, at least by the numbers: Based on survey data, after three years the children's knowledge of nutrition issues increased 30 percent, use of high-fat foods fell 14 percent, use of high-sodium foods fell 16 percent, and use of high-sugar foods fell 3 percent.

There were no significant changes in body fat, blood-pressure or cholesterol levels as a result of the program, but Dr. Stewart says that's to be expected. "The kids are normal to begin with -- they're normal, healthy kids. The goal is to keep them healthy long-term."

The idea that children need nutrition information to make dietary changes that will ensure good health in adulthood has been gaining steam in recent years as it becomes clearer that some of the most deadly conditions in adults are diet-related -- heart disease, hypertension (high blood pressure) and even cancer.

Health education is a statewide mandate in Maryland, which has established seven health goals. Most students in kindergarten through 12th grade get a series of lessons on fitness, nutrition, mental health awareness, alcohol and substance abuse awareness, among other topics, according to Larry Herrold, supervisor of health education for Baltimore County public schools.

"I think that it's critically important" to instill good nutrition information in children, says Ellen Haas, former consumer advocate at Public Voice for Food and Health Policy and now assistant secretary of agriculture for food and consumer services. USDA has been conducting hearings on ways to improve nutrition of the nation's school lunch program.

After more than 300 witnesses and 2,400 written comments, Ms. Haas says, "We heard it time and time again: Children's dietary patterns begin when they're young. And their risk situation also begins when they're young . . . One of the things we asked in the hearings was, 'What are the consequences of children's dietary patterns?' We heard repeatedly that children do have serious outcomes from a diet that's high in fat and saturated fat." School lunch initiative

USDA is about to launch what Ms. Haas describes as "a major initiative" with regulatory and departmental actions, as well as some legislative changes, to ensure that meals served in schools meet the dietary guidelines issued by USDA.

There are 25 million children in the program, and half of them, Ms. Haas says, come from families that fall below the poverty level. "For many of them it's the only nutritious meal they get."

The question of how much nutrition information children need stirred controversy last month at a San Francisco conference on gastronomy sponsored by the American Institute of Wine and Food, when Ms. Haas and other nutrition-education proponents were countered by some food professionals, including noted teacher and cookbook author Marion Cunningham, who

contended that giving "rigid and restrictive messages" about food would produce undue fear in children.

And one speaker, Dr. Ronald Kleinman, chief of the pediatric and gastrointestinal unit at Massachusetts General Hospital, suggested that data so far do not support concern over childhood consumption of fat and sugar, and that parents would do well to worry about other threats to longevity, such as street violence and suicide.

"I know what I had to say was not perfectly in sync with what some of the others said," Dr. Kleinman says. "It's still an open question -- we don't know what determines our eating habits over a long period of time. Most people don't eat the same things as they did when they were teen-agers. There are a lot of powerful influences on what you eat and what tastes good to you.

"I think the primary focus should be on providing appropriate, and enough, nutrition to all youngsters to allow them to grow appropriately and function appropriately -- to play sports, or to pay attention. A second very important concern is to teach children how to survive childhood -- to make them aware there's a link between eating and health, and that they can to some extent control their health." But he says, "there are other things parents need to pay attention to," such as making sure children get enough exercise and that they avoid risky behaviors such as riding in a car without seat belts.

Still, he says, "children need to be inquisitive about food. We need to teach children how to ask questions and give them the resources to get answers."

In the FRESH program, children get a series of lessons four times a year, designed to arm them with knowledge about the risks of poor nutrition and risky behavior and to give them general health guidelines.

Four lessons

"The first lesson is on heart disease," says Colleen Seemans, the health program coordinator. "It's on why people have heart attacks . . . We try to use a lot of visual aids -- we show them drinking straws clogged with [solid shortening], or we put fat in plastic bags to show them how much fat is in their favorite foods." For instance, she says, a meal of 6 chicken nuggets has 3.7 teaspoons of fat, while a garden salad has only 2 teaspoons.

The second lesson is on the new U.S. Department of Agriculture Food Guide Pyramid, which groups foods according to how often they should show up in a daily diet.

The third lesson is on fast food and dining out. When she teaches that segment, Ms. Seemans says, "I'm not going in there saying don't ever eat at fast-food restaurants. We're saying, there's better choices there." They could choose a grilled sandwich, instead of one that's fried, for instance, or a plain hamburger, topped with lettuce and tomato. The last lesson is a wrap-up of all the other information and includes a segment on exercise.

This year, FRESH is working with younger children, second- and third-graders, because younger children seem more receptive to the message.

As the program goes on, Dr. Stewart says, "We're trying to fine-tune our teaching approach. We're also trying to look at the relationships among risk factors in children, to see to what extent do they go together. Do fat kids, for example, kids who are obese, have a greater risk of high blood pressure, high cholesterol? . . . One common finding among all the kids we've worked with is that obesity seems to be the strongest predictor of high cholesterol and high blood pressure."

But overall, Dr. Stewart says, "the issue in not whether kids should eat healthy. It's a question of what approach do you take to teaching this to kids. Our approach is more what we call a public-health approach, where we're providing broad general guidelines that hopefully will cause a lot of little changes in a lot of people, and over time that should have a significant effect on the rate of heart disease in the population.

"If you look at the studies that have been done in adults, for every 1 percent decrease in cholesterol in the population, there's approximately a 2 percent decrease in the rate of heart disease. So that even if you make small changes in children, if it results in their cholesterol just being a little bit lower when they're older, it could have a fairly dramatic impact on their rate of heart disease."

And that, from a public-health standpoint, makes a lot of sense.

"If you think of food as a medicine -- which it is, you really are what you eat, to a large extent," Dr. Stewart says, "it's the cheapest form of medical intervention. It's free, and it works."