FOR about a decade, geneticist Tim Spector of King’s College London ate the same thing every day: a tuna and sweetcorn sandwich on brown bread, followed by a banana. He thought it was a healthy choice, until he turned the microscope on himself and discovered that it was about the worst possible thing he could eat. He was having huge post-lunch surges of sugar and fat in his bloodstream, both of which are known risk factors for diabetes, heart disease and obesity.
But just because tuna sandwiches are bad for Spector doesn’t mean they are bad for everyone. Far from it: for some people, they are super healthy. The same is true of almost any food, even things like ice cream and white bread that have long been considered universally bad news.
Recent research by Spector and others has revealed that our response to food is highly individualised and that, consequently, there is no such thing as a healthy diet that works for everybody. In fact, people respond to food in such idiosyncratic ways that everybody needs a personalised nutrition plan. Now he and others, including the US National Institutes of Health, are seeking to deliver such plans in a healthy eating revolution that is being called “precision nutrition”.
The findings could also explain why decades of one-size-fits-all dietary advice has failed to halt the global epidemic of obesity and diabetes and why nutrition science has consistently failed to produce a straight answer to its most pressing question: what constitutes a healthy diet?
The idea of diet as a major determinant of health goes back to at least …
