The number of sufferers has doubled over the past two decades, and has now reached epidemic proportions.
Doctors believe it's largely a lifestyle condition that can be prevented.
But in the meantime, it's contributing to a massive rise in kidney disease. I started feeling sick, drinking litres and litres of water overnight. I had blurred vision all the time and little cuts that wouldn't heal. I went to the doctor about it and they told me I was diabetic. Since being diagnosed with diabetes 16 years ago, Barry Hodder has reshaped his lifestyle.