body image vs idea

body image and idea both are nouns.

Word	Noun	Adjective	Verb	Adverb
body image	Yes	No	No	No
idea	Yes	No	No	No

As nouns, idea is a hypernym of body image; that is, idea is a word with a broader meaning than body image:

body image (noun)	idea (noun)
an individual's idea as assessment of his or her own body	the content of cognition; the main thing you are thinking about
	your intention; what you intend to do
	an approximate calculation of quantity or degree or worth
	a personal view
	(music) melodic subject of a musical composition