Just to be clear, when you say "rule" in your last sentence, you're referring to the rule that eating large amounts of high-fat food can cause a body to carry more body fat? If so, I'm in full agreement; there is indeed a reason for that rule, and it has everything to do with human biology. Not sure what that has to do with people's feelings, though.
If I'm misunderstanding your use of the word "rule", I apologize, and I hope you will correct me.