Aldous Huxley wrote that “Medical science has made such tremendous progress that there is hardly a healthy human left.” Changes to the American Diabetes Association (ADA) guidance on the diagnosis of pre-diabetes in 2010 make this statement even more true.1 If implemented globally the guidance could create a potential epidemic, with over half of Chinese adults,2 for example, having pre-diabetes, a national burden of around 493 million people.

Pre-diabetes is an umbrella term and the most widely used phrase to describe a blood concentration of glucose or glycated haemoglobin (HbA1c) that lies above normal but below that defined for diabetes. We explore the evidence and value of pre-diabetes as a category or diagnosis (box 1) and argue that current definitions risk unnecessary medicalisation and create unsustainable burdens for healthcare systems.