Experts say a healthy diet should include 10 portions of fruit and vegetables a day, double that of New Zealand's 5+ A Day campaign.
The advice comes after a 12-year University College London study which found that people who ate at least seven portions of fruit and vegetables each day were 42 per cent less likely to die from any cause over the course of the study.
Lead author Dr Oyinlola Oyebode of UCL's department of epidemiology and public health said: "The clear message here is that the more fruit and vegetables you eat, the less likely you are to die at any age. My advice would be, however much you are eating now, eat more."
Professor Simon Capewell, of the department of public health at the University of Liverpool, said the advice should be 10 portions a day. "Humans are designed to be omnivorous: a handful of nuts, seeds, fruit and the occasional antelope. We're not meant to be eating junk food."