This is the 859th most frequent Persian word.
غذایی
Related to food or dietary.
In this sentence, 'غذای' is used as a noun meaning 'food', specifically referring to Iranian cuisine.
من به غذای ایرانی علاقه دارم.
I am interested in Iranian food.
Here, 'غذایی' modifies 'مواد' (materials), forming the compound 'مواد غذایی' which means 'food items' or 'groceries'.
مواد غذایی تازه بهتر هستند.
Fresh food items are better.
In this usage, 'غذایی' is an adjective describing 'رژیم' (diet), indicating it is related to food.