macrobiotics vs dietetics

macrobiotics and dietetics both are nouns.

Word	Noun	Adjective	Verb	Adverb
macrobiotics	Yes	No	No	No
dietetics	Yes	No	No	No

As nouns, dietetics is a hypernym of macrobiotics; that is, dietetics is a word with a broader meaning than macrobiotics:

macrobiotics: the theory of promoting health and longevity by means of diet (especially whole beans and grains)
dietetics: the scientific study of food preparation and intake

macrobiotics (noun)	dietetics (noun)
the theory of promoting health and longevity by means of diet (especially whole beans and grains)	the scientific study of food preparation and intake