Be careful. Many of the desserts that are offered as a "healthy alternative" are "no sugar added", not "sugar free". Some are dripping in natural sugars (sorbet, for example), and others have sugar alcohol used as a sweeter.
At Narcoossee's, we were offered a no-sugar added dessert that was a flourless cake (i.e., nut flour, chocolate, eggs, and butter) topped with no-sugar-added ice cream and whipped cream with a garnish of fruit. It was actually worse, for a diabetic, than having the regular almond-crusted cheesecake!
Many of the restaurants have a cheese plate as an option for dessert (in some cases, not even advertised), so there will always be something there for you.