The Knesset yesterday passed a law banning the use of underweight models in advertising. The so-called "Photoshop law" also requires that any ad agency digitally altering photos to make models look thinner must disclose the fact in the advert.

The legislation is an effort to change idealized perceptions of beauty that, according to evidence presented to the Knesset, encourages eating disorders such as anorexia.

The law also bars the use of overly thin images from foreign advertising here, as defined by the commonly used medical measure of body mass index. Models with an index of 18.5 or less - or who appear to have such a low index - will not be allowed to appear in advertising.

Data from the Knesset's Research and Information Center presented at legislative hearings revealed that there are about 1,500 children, including teenagers, diagnosed with eating disorders in Israel annually. Evidence presented to the Knesset showed that exposure to idealized media images of bodies is one risk factor in developing an eating disorder, by glorifying the thin body.

Modeling agents yesterday protested the harm they say the law will inflict on the careers of models whom they say are healthy, despite their low body mass indexes. "The indexes on which the law is based are arbitrary and are not appropriate for every model. I know many models who are totally healthy girls who might be disqualified because of the law," said Eli Edri of the Roberto Models Agency. He said some models are naturally thin and cannot gain weight. "Such a law would disqualify them without determining whether they are really sick or not."

Alisa Gourari, an 18-year-old model who was runner-up in the World Super Model competition, has modeled for Max Mara and Valentino. She has starred in a number of Israeli advertising campaigns but is too thin to meet the requirements of the new law. She said the debate over underweight models is important, but she too said the law applied limits without regard to whether the model was healthy at his or her weight.

"I am 1.80 meters tall and weigh 55 kilograms. That's absolutely below the index the law provides," she said, adding: "Since I was small, even before I was a model, I tried to gain weight but I couldn't."

She said that despite following dietitians' advice, she remained at the same weight. "For someone like me, for whom it's genetic, I will be arbitrarily disqualified from working and realizing my life's dream," she said, "and that's a shame."