Without the body, nothing else is possible. That is to say, the body is the necessary condition of all earthly existence. Does it follow from this that the body is the essence of life, to which we must look for all our understanding of ourselves and our choices? If you answer yes, then you are a materialist.
Without the feelings, which are rooted in our physical existence, none of the subsequent developments of life — empathy, community, language, law — would have been possible. That is to say, feelings are a necessary condition of all human life. Does it follow from this that the primitive passions, uninformed by reason, are the human essence, to which we must look in search of our deepest nature and proper goals? If you answer yes, then you are a romantic.
Hence, romanticism is a natural offshoot or byproduct of materialism.