The "Why" rapper raised eyebrows this week when a Brooklyn pizza shop posted an image on social media showing his custom order ... a cheese pizza with the center cut out, leaving behind nothing but a ring of crust.

Jadakiss tells us the crust has been his favorite part of pizza since he was a kid ... and now that he's 44, he cuts right to the chase and skips everything except the crust because he's on a health kick, and dairy is not part of his diet.

Jadakiss says that's been his drill for years -- cheese pizza, hold the cheese.

Kiss says the viral image is actually from a year ago, and his good friend, the owner of Cuts and Slices pizza shop in Brooklyn, re-posted it after another pizza parlor announced it was now offering a pie made only of crust.

Jadakiss' odd order sent the Internet into a tizzy ... but he's not dishing back the hate he's received. He says pizza lovers should order their pies however they want, and he's got nothing against peeps who pile on cheese. It just ain't for him.