This always happens around family members. Something happens that leads to us talking about weight/calories/exercise/whatever. Inevitably, if the person I'm talking to is fat, they have a ton of excuses at the ready for the topic we're discussing. I mercilessly refute all of them. They're family, so I'm not going to tell them they're a useless fat, but I'm also certainly not going to let them live in fantasyland. They're going to hear the truth until they do something about it. Unfortunately, so far this has only worked on one. The rest are either already fit or have been fat for ages.