听力原文： The latest diet fad is not really new. It is called the Scarsdale diet and was originally outlined 20years ago by Dr. Herman Tarnower, a cardiologist and internist from Scarsdale, New York. The diet became popular when people from Scarsdale who had used the diet successfully sent mimeographed copies to their friends in other parts of the country. Since his book the Complete Scarsdale Medical Diet was published last year, he has sold 270000 copies, and the diet has become a national pastime. In his book, Dr. Tarnower claims that a dieter who follows his plan will be able to lose up to 20 pounds in 2 weeks. The diet is very simple, but it requires a great deal of discipline. For two weeks at a time the dieter must follow a strict menu that does not provide for any substitutions by the dieter. There is no alcohol, no oil and no sugar allowed, and raw celery or carrots are the only snacks allowed. Although the amount of food that the dieter may eat is not limited, most dieters average less than one thousand calories a day. Many complain that their energy levels are low, but most are very satisfied with the results. why is the weight loss plan called the Scarsdale diet?