CHICAGO: Very obese older men hoping to live longer may be let down by a new long-term study that found weight-loss surgery didn't increase survival for people like them _ at least during the first seven years. Prior studies have found stomach stapling and other obesity surgeries improved survival rates after two to 10 years. The new study in mostly older male veterans suggests one of two things: Not everyone gains equally from surgery, or a survival benefit may show up later in older men, after more years of follow-up. Previous findings came mainly from studies of mostly younger women. “Nearly all prior studies have found bariatric surgery to be associated with reduced mortality. But those studies were conducted on very different patient populations using less rigorous methods,” said lead author Matthew Maciejewski of the Veterans Affairs Medical Center in Durham, North Carolina. The patients' organ damage from obesity could have been too far along for weight loss surgery to reverse it, some experts said. “It may be too little too late,” said Dr. Philip Schauer of the Cleveland Clinic's Bariatric and Metabolic Institute. He was not involved in the study. “You may have to intervene earlier for a survival benefit.” Evidence has been mounting for the health benefits of obesity surgery, so the new results may surprise some people. US doctors now perform more than 200,000 obesity surgeries a year at an estimated cost of $3 billion to $5 billion. Schauer said a definitive study on survival could cost $200 million. The new study, released Sunday to coincide with a medical meeting, will appear in Wednesday's Journal of the American Medical Association. Benefits of obesity surgery _ improved quality of life, weight loss and reductions in diabetes symptoms, blood pressure and sleep apnea _ may be reason enough to choose the treatment. “These results are not an indictment of surgery,” Maciejewski said. He and his colleagues plan to follow the patients longer to see if a survival benefit shows up 10 to 14 years after surgery.