Next month's Sao Paulo Fashion Week added the minimum-age requirement to a previous rule that modeling agencies present a signed medical certificate proving their models are in good health.

"Beauty and fashion is about health in the first place," Fashion Week Creive Director Paulo Borges said in a statement.

Young models anxious to begin their careers may become frustrated if they aren't immediately successful, the organization said in a statement. If they believe the way to success is a rail-thin body, rising models may starve themselves to meet the perceived beauty standard.

The world of high fashion and modeling has long been targeted by critics who say it encourages women and girls to emulate models.

In September, Madrid's Fashion Week banned models with a body mass index of less than 18. Body mass index is a calculation doctors normally apply to study obesity, and anyone with an index below 18.5 is considered underweight.

While the Sao Paulo event put no specific body-mass requirement on models, its statements Thursday reflect the local industry's concern about models' health following the death of Ana Carolina Reston of generalized infection caused by anorexia nervosa, a disorder characterized by an abnormal fear of becoming obese. The 5-foot-8 inch model weighed 88 pounds at the time of her death.

Brazilian TV viewers are also following the drama of young Giselle, a teenage character in the prime-time telenovela "The Pages of Our Lives" who suffers from bulimia.

Sao Paulo Fashion Week takes place Jan. 24-29. It will feature collections from dozens of Brazilian designers.