It depends on what diet you follow, if you follow South Beach, Atkins or Tony Ferguson.

For me fat isn't a problem, I lose weight with it. But that doesn't mean as said above I eat a cup of lard at every meal. But I do steer clear from low fat products as they often substitute with Sugar or fillers that end up being higher in carbs, so for me its bad. For example I am better off having a dollop of cream in my coffee than milk and especially NOT skim milk. But I prefer milk so I take my carbs from their from somewhere else and it all balances. Also remember everyone is different so it depends on how your body works and the diet you are doing.