A problem with this study is that it used Nurses. Having worked with Nurses and been married to one, I know that their eating habits, due to their often hectic work routine, are not ideal. A soda or other sugary drink on an empty stomach in lieu of a more substantial snack may not do the same thing as a soda consumed during lunch, for example.
The link between the expression of Type II Diabetes and weight has been well established. Anything that contributes to weight gain will be a risk factor.