What is the meaning of "form" here? What is difference from just saying "wasteful food"?
Native speaker’s answer
Rebecca
Form here is being used to mean type. So he is saying that red meat is a particularly wasteful type of food. He's using it to highlight that it is more wasteful than other kinds of meat. It is simply being used for emphasis and you are right he could have said wasteful food. Ex: Red meat is a particularly wasteful food.