Sitting at a table at Balthazar in downtown Manhattan, Peter Rahal spears a piece of smoked salmon on his plate and ignores the nearby toast. The 38-year-old cofounder of nutrition bar brand RxBar ...

Increasing health span is also more in line with what many people want. “I can tell you that older people are not afraid of dying,” said Dr. Luigi Ferrucci, a geriatrician and the scientific ...