That’s a good question. There are lots of reasons why someone can get diabetes – for example, Type 1 diabetes is partly inherited, but has to be triggered by some external cause. Some scientists think this trigger is a virus, but it also might be due to environmental triggers (such as diet or lifestyle). Because there are so many different ways in which diabetes can be triggered, it’s difficult to isolate a single cause, or group of causes. We will figure it out eventually though!