As a weight loss strategy IF'ing is OK, but it definitely contributes to some physiological changes. So back to your question ....yes you can eat fruit (IF'ing allows for a bit more leeway in this regard IMO), just don't forget to eat all the other stuff.
Studies on fasting seem to indicate positive physiological changes regardless of the makeup of the meal (some studies show the same calories and foods consumed in that smaller window). Its kinda cool, cause it seems just limiting the hormonal array associated with processing food has a positive effect.
Have you looked at any of the IF sites liked "Leangains"? -http://www.leangains.com/2010/04/leangains-guide.html Another useful IF link -http://rippedbody.jp/ The IF calculator is useful for determining your macronutrient intake. -http://www.1percentedge.com/ifcalc/
Hope this helps.