There's a 100% correspondence with having the genes. That is, all people with Type II diabetes have the genes. On the other hand, not all people with the genes develop Type II diabetes, and some people with the genes who have developed Type II diabetes, actually turn things around and cease to exhibit symptoms.
Which means that you can avoid Type II diabetes, or at least the most serious consequences, with a highly controlled diet and exercise.
The diet looks very much like that of pre-agricultural human beings ~ big game hunters in fact. The amount of exercise is not out of reason, but is more like that experienced by nomadic hunter/gatherers than modern, sedentary populations.