Too many of us look at food as if it were a luxury good. We need to stop this because pleasurable foods tend to be bad for us. The thing about luxury objects like jewelry is that jewelry by itself is not harmful. A watch from Patek Phillipe or a car from BMW is not going to hurt you (it might hurt you economically though).
However, luxury food can hurt you! That is the difference. When I talk about luxury food I am not talking about caviar or expensive wine. I am talking about KFC. I consider something as a luxury if it gives you pleasure. I think therefore it is necessarily to look at food not as a luxury good but as a tool for survival. Get your luxuries elsewhere where it is harmless, e.g. from watching TV (although too much TV might get in the way of exercise).