> Can eating too much fruit contribute to diabetes? 

Clearly it can, especially dried fruit.  Heck, eating too much protein could contribute to diabetes as excess protein is converted to glucose.

I subscribe to Phinney's "optimum therapeutic window for human metabolism" whereby about 15% of daily energy expenditure is taken as protein.  The other 85% or so should be fat.  (Remember that's as *calories*, not weight or volume).

Jim