It’s no secret that many in our society have a complex and often unhealthy relationship with food. But, for an estimated 8 million people who suffer from eating disorders in the United States — most of them adolescent girls and young women — the problem goes well beyond too much fried food or the occasional need to wallow in a bowl of chocolate ice cream.

Little is known about why they occur or how they can be prevented: the compulsive dieting, even in the face of emaciation, associated with anorexia nervosa; the binge-and-purge behaviors characteristic of bulimia nervosa; or the compulsive overeating — minus the self-induced vomiting or other purging behavior — of people with binge-eating disorder. But experts such as Michael Strober Ph.D. ’75, director of the Eating Disorders Program at Resnick-UCLA Neuropsychiatric Hospital, point out three simple truths:

• Eating disorders can cause serious health problems and can be fatal.

• They are treatable, but success is far more likely if they are addressed early and by knowledgeable professionals.

• They can be easily missed, particularly given that sufferers are not only unlikely to seek help, but are motivated to keep their behaviors to themselves.

The three major eating disorders share certain characteristics, says Strober, who also serves as the Franklin Mint Professor of Eating Disorders at UCLA’s David Geffen School of Medicine. “In all of them, we see the overvaluation of weight and shape and their disproportionate effect on self-concept; distorted eating attitudes, particularly the belief that small amounts of food will cause significant weight gain; a preoccupation with issues related to eating; and an excessive fear of weight gain,” he explains.

The consequences can be severe. The Academy for Eating Disorders says that up to 10 percent of women with anorexia nervosa may die due to anorexia-related causes — 12 times the risk of death for their same-age peers without the disorder. In addition, because symptoms tend to persist for long periods of time and complete recovery typically takes years, bone disease and other complications from malnourishment are common. And people with bulimia nervosa experience maladies ranging from irritation of the esophagus and bruising from induced vomiting to erosion of dental enamel and, in the most extreme cases, life-threatening electrolyte abnormalities.

Too often, eating disorders are not tackled at a time when it would be easier to intervene, because the clues can be subtle. Still, although sufferers rarely volunteer that they have a problem, when appropriately confronted, many will experience a sense of relief. Strober notes, though, that anger and denial are also common. So he advises that family members or friends “be very calm, noncritical and detailed in the description of what you’re observing, and be persistent in the discussion of how important it is that this be addressed.”

Here’s what to look for if you believe a friend or loved one is in jeopardy:

Excuses to Avoid Meals. Anorexic individuals offer frequent rationalizations for not eating: They already ate with a friend, or they’re going to eat later. Those with bulimia and binge-eating disorder are often uncomfortable eating around others and may offer similar explanations to avoid having to do so.

Unusual Eating Behavior. Cutting food into very small pieces and moving it around on the plate to avoid eating it are hallmarks of anorexia nervosa, while bulimics are more likely to eat rapidly. Odd combinations of food are also common, such as using mustard in yogurt or ketchup on cereal. For different reasons, people with either eating disorder are likely to take very small portions when eating with others. Individuals with bulimia may consume large amounts of water or diet soda to make vomiting easier.

Distorted Body Image. A preoccupation with weight tends to lead to excessive dieting and exercise to the point of excess. People with eating disorders often wear baggy clothes to hide their shape, and avoid looking in mirrors.

Mood and Mind Effects. Increased anxiety may be apparent around meal times, but even away from food, someone with an eating disorder will often show the mental effects of malnutrition that can include increased irritability, poor concentration, and impaired memory and cognitive abilities. Fatigue, lack of motivation, sleep irregularities and other symptoms of depression are also potential warning signs.

Physical Signals. The most obvious sign that a loved one may be suffering from anorexia nervosa is, of course, a dramatic weight loss not related to any other illness. But there may be earlier physical signals resulting from the gradual elimination of nutrients from the diet, such as dry hair or hair loss, brittle nails and changes in skin complexion, as well as a lack of energy or constantly feeling cold. On the other hand, when there is no obvious change in weight in someone who has been eating ravenously, it points to the possibility of bulimia nervosa. Physical symptoms related to induced vomiting include discolored or callused fingers; discolored teeth and swollen or bleeding gums or cheeks; and stomach pain and constipation or diarrhea.

Secrecy. In the case of anorexics, the need to wear baggy clothes or to dress in layers is often not just an effort to hide their bodies from themselves, but also to keep their weight loss from being discovered by others. Those with bulimia nervosa and binge-eating disorder tend to go to even greater lengths to keep their behaviors hidden, and signs of this secretive behavior include indications of late-night eating, large quantities of food missing, food found hidden or hoarded, and discoveries of numerous empty wrappers or containers in the trash. Other signs include use of laxatives or diuretics along with trips to the bathroom immediately after every meal and signs of vomiting — a smell, or evidence suggesting a cover-up such as running water to hide the sound, or the consistent use of mints or gum when emerging from the bathroom.