It means that you cannot wrong yourself when it comes to eating, and you must treat food well. This is a sign of living seriously and loving life.

The next sentence is that people are iron and rice is steel. It is better to be a foodie than a fool.

"Only good food cannot be disappointed. People are like iron, rice is like steel. It is better to be a foodie than a fool."

This sentence uses a self-deprecating way to express the love for food, while also emphasizing that foodies are better than those who don’t know what food is.