SODIUM - that's what worries Greye Dunn. He thinks about calories, too, and whether he's getting enough vitamins. But it's the sodium that really scares him.

"Sodium makes your heart beat faster, so it can create something really serious," said Greye, who is 8 years old and lives in Mays Landing, N.J.

Greye's mother, Beth Dunn, the president of a multimedia company, is proud of her son's nutritional awareness and encourages it by serving organic food and helping Greye read labels on cereal boxes and cans.

"He wants to be healthy," she says.

Ms. Dunn is among the legions of parents who are vigilant about their children's consumption of sugar, processed foods and trans fats. Many try to stick to an organic diet. In general, their concern does not stem from a fear of obesity - although that may figure into the equation - but from a desire to protect their families from conditions like hyperactivity, diabetes and heart disease, which they believe can be avoided, or at least managed, by careful eating.

While scarcely any expert would criticize parents for paying attention to children's diets, many doctors, dietitians and eating disorder specialists worry that some parents are becoming overzealous, even obsessive, in efforts to engender good eating habits in children. With the best of intentions, these parents may be creating an unhealthy aura around food.

"We're seeing a lot of anxiety in these kids," said Cynthia Bulik, the director of the eating disorders program at the University of North Carolina at Chapel Hill. "They go to birthday parties, and if it's not a granola cake they feel like they can't eat it. The culture has led both them and their parents to take the public health messages to an extreme."

Tiffany Rush-Wilson, an eating disorder counselor in Pepper Pike, Ohio, has seen the same thing. "I have lots of children or adolescent clients or young adults who complain about how their parents micromanage their eating based on their own health standards and beliefs," she said. "The kids' eating became very restrictive, and that's how they came to me."

Certainly, not all parents who enforce rules about healthy food - or any dietary plan - are setting their children up for an eating disorder. Clinical disorders like anorexia nervosa and bulimia, which have been diagnosed in increasing numbers of adolescents and young people in the last two decades, are thought by researchers to have a variety of causes - including genetics, the influence of mass media and social pressure.

To date, there have been no formal studies on whether parents' obsession with health food can lead to eating disorders. Some experts say an extreme obsession with health food is merely a symptom, not a cause, of an eating disorder.

But even without firm numbers, anecdotal reports from specialists suggest that a preoccupation with avoiding "bad" foods is an issue for many young people who seek help.

Dr. James Greenblatt, the chief medical officer at Walden Behavioral Care, a hospital specializing in child and adult eating disorders in Waltham, Mass., estimates that he has recently seen about a 15 percent rise in the number of his young patients who eat only organic foods to avoid pesticides.

"A lot of the patients we have seen over the last six years limited refined sugar and high fat foods because of concerns about gaining weight," he said. "But now, these worries are often expressed in terms of health concerns."

Lisa Dorfman, a registered dietitian and the director of sports nutrition and performance at the University of Miami, says that she often sees children who are terrified of foods that are deemed "bad" by parents. "It's almost a fear of dying, a fear of illness, like a delusional view of foods in general," she said. "I see kids whose parents have hypnotized them. I have 5-year-olds that speak like 40-year-olds. They can't eat an Oreo cookie without being concerned about trans fats."

Dr. Steven Bratman of Denver has come up with a term to describe people obsessed with health food: orthorexia. Orthorexic patients, he says, are fixated on "righteous eating" (the word stems from the Greek word ortho, meaning straight and correct).

"I would tell them, 'You're addicted to health food.' It was my way of having them not take themselves so seriously," said Dr. Bratman, who published a book on the subject, "Health Food Junkies," in 2001.

The condition, he says, may begin in homes where there is a preoccupation with "health foods."

Many eating disorder experts dispute the concept. They say that orthorexia, which is not considered a clinical diagnosis, is merely a form of anorexia nervosa or obsessive compulsive disorder.

Angelique A. Sallas, a clinical psychologist in Chicago, says the idea of a "health food disorder" is practically meaningless. "I don't think the symptoms are significantly different enough from bulimia or anorexia that it deserves a special diagnostic category," Dr. Sallas said. "It's an obsessive-compulsive problem. The object of the obsession is less relevant than the fact that they are engaging in obsessive behavior."

Dr. David Hahn, the assistant medical director at the Renfrew Center, an eating disorders clinic in Philadelphia, also thinks that orthorexics are anorexics in disguise. "I see many patients that are overly concerned with the quality of their food, and that's the way they express their eating disorder," he said.

But whatever the behavior is called, those who have lived through a disorder fueled by an obsession with healthful eating say that the experience can be agonizing. Kristie Rutzel, a 26-year-old marketing coordinator in Richmond, Va., began eliminating carbohydrates, meats, refined sugars and processed foods from her diet at 18. She became so fixated on eating only "pure" foods, she said, that she slashed her daily calorie intake to 500. Eventually, her weight fell to 68 pounds and she was repeatedly hospitalized for anorexia.

Today Ms. Rutzel, who said she is normal weight, often talks to young girls in schools and churches about the perils of becoming health-food obsessed.