Meanwhile, there is a dearth of evidence that caloric restriction slows ageing in humans. Observational studies have found that people of average weight tend to live longest3. Nir Barzilai, a gerontologist at Albert Einstein College of Medicine in New York, says that the centenarians he studies have led him to believe that genetics is more important than diet and lifestyle. “They’re a chubby bunch,” he says.
A more nuanced picture would suit Ingram, who enjoys an occasional feast of Louisiana crawfish. Ingram says that he looks forward to studies of how diet composition, rather than caloric intake, affects ageing. “Is the human lifespan fixed?” he asks. “I still don’t believe that for a minute.”
This article is reproduced with permission from the magazine Nature. The article was first published on August 29, 2012.