Symposium on obesity (First Part).

NAASO Representative, International Association for the Study of Obesity, Director, Center for the Study and Treatment of Obesity, Merida, Yucatan, Mexico; Cordinator of Metabolic and Clinical Research, Mexican Health Foundation, Yucatan Chapter. Laval University PEPS, Ste-Foy, Quebec, Canada. Professor of Psychiatry, University of Pennsylvania, Philadelphia, PA. USA. Endocrinology Department Clinica de Merida, Merida, Yucatan, Mexico. Weight Control Unit, St. Lukes Roosevelt Hospital, New York, NY, USA.