In  a 2013 study, Professor Ambady Ramachandran (India Diabetes Research Foundation), found that almost a third fewer men in a high-risk group went on to develop diabetes if they received between two and four texts a week giving advice on diet and exercise.

“This is a big – and surprising – effect,” says Professor Nick Wareham (MRC Epidemiology Unit). Prof Ramachandran’s study involved a relatively small sample, but such was its promise that he and Prof Wareham have teamed up to see whether text messaging might be scaled up to a larger population. Prof Wareham and colleagues use a combination of a risk score that they have developed, which looks at factors such as age, sex and weight, and a simple blood test to identify people at risk of developing diabetes: these are the individuals who are targeted by the text messages.

While targeted strategies aimed at high-risk individuals are likely to be effective, there is no way they could be rolled out to 20 million people. Prof Wareham says, “If you had to individually counsel that many people, it would be unaffordable. Simple, pragmatic, scalable approaches are the only ones that are feasible.”