The first national poll to measure eating disorders among American women has determined that about 2 million of America's approximately 37 million women between the ages of 19 and 39 have suffered or are suffering from anorexia nervosa or bulimia or both.

In addition, an estimated 1 million teen-age girls suffer symptoms of one or another of these disorders.

The poll tends to confirm estimates of the widespread nature of these disorders made by specialists who treat them. Victims of anorexia nervosa can literally starve themselves to death in an effort to become increasingly thinner. Bulimics engage in periodic compulsive binges in which as many as 20,000 calories may be consumed at one sitting, followed by equally compulsive purging, either by self-induced vomiting, abuse of laxatives or abuse of emetics such as syrup of ipecac.

Both disorders can cause sometimes fatal heart irregularities and a variety of other health problems ranging from pervasive tooth decay to gastric ulcers, cessation of menstrual periods and loss of fertility.

Dr. Sue Bailey, director of the eating disorders program at the Washington Hospital Center, serving as medical consultant and spokesman, with pollster George Gallup Jr., on the eating survey, said that for the first time "specialists can look at the impact of eating disorders across the board. It dispels the myth that this is only a teen disease."

The poll, done under the auspices of Comprehensive Care Corp., which runs a network of anorexia nervosa and bulimia treatment centers, also found that the "socioecomonic boundaries are very unclear," Bailey said. "We know we have treated housewives, doctors, lawyers, a country-western singer and a circus performer at the Washington Hospital Center, but the poll confirms that the variety of backgrounds is not just anecdotal." According to the poll, the illness strikes across educational, ethnic and socioeconomic lines.

Another finding Bailey said she found "startling" was that 16 percent of those women polled considered themselves on a perpetual diet. Sixty-four percent said they would like to lose weight but about the same percent said they did not believe losing weight would improve their lives.

Bailey noted that the obsessive nature of the practices was demonstrated by a finding that 17 percent of the women admitted to "excessive exercise" to burn off calories absorbed in binges. She said the question was "spelled out explicitly to mean exercise for 'several hours' at a time."

Bailey believes that the easy availability and preparation of food, the increasingly thin "ideal" of femininity, the current fitness craze and a perception by today's women of a need "to be perfect," has resulted in these widespread eating disorders. "The way food is obtained and stored and prepared and consumed has changed more drastically in the last 40 years than in the preceding 4,000," she said.

She finds it "frightening" that eating disorders are considered a kind of "in" thing to have among today's teen-agers.

A survey she did in this area found that "in one college group, 43 percent said they would consider trying to throw up after binging. And 28 percent of a group of eighth graders said the same. If they would even consider that, it shows they are vulnerable to developing eating disorders in their twenties, thirties and forties," Bailey said.