Are overweight people the only ones at risk of diabetes or are they just more likely to get it?

No: Being overweight is clearly the biggest risk factor for type 2 diabetes. However, lack of exercise, genetics, age and some medications (antipsychotics, steroids and mood stabilizers) can also contribute. The only ones that can be changed are exercise, weight and medications. These are particularly important to watch if you have a first degree relative with type 2 diabetes.