Obesity is a national health crisis—that  much we know. If current trends continue, it will soon surpass smoking in the U.S. as the biggest single factor in early death, reduced quality of life and added health care costs. A third of adults in the U.S. are obese, according to the Centers for Disease Control and Prevention, and another third are overweight, with Americans getting fatter every year. Obesity is responsible for more than 160,000 “excess” deaths a year, according to a study in the Journal of the American Medical Association. The average obese person costs society more than $7,000 a year in lost productiv­ity and added medical treatment, say researchers at George Washington University. Lifetime added medical costs alone for a person 70 pounds or more overweight amount to as much as $30,000, depending on race and gender.