By Andrew M. Seaman (Reuters Health) – Obese people who undergo a certain kind of weight-loss operation after age 35 may live longer than obese people of the same age who don’t have the surgery, a study suggests. The findings, reported in JAMA Surgery, show that the so-called gastric bypass operation is associated with a mortality benefit along with its better-known “metabolic” benefits, said lead author Lance Davidson, of Brigham Young University in Provo, Utah. Past research has found weight loss surgeries are tied to reduced deaths from any cause, cancer and heart disease.