Soda leaches minerals from your bones:
http://www.mayoclinic.com/health/ost...N=risk-factors
Sugar-free caramel probably just means there are other weird chemicals in there.
You don't mention what size latte you get, but maybe you could get a smaller one. Personally, my experience with low fat diets is that I am hungry and cranky all the time, I end up eating a lot of unnatural, processed "foods", and ultimately it's just not good for me. So when I order my decaf mocha, I get fatty milk and whip =) It satisfies the craving in a way that skim milk never could.