An apple a day keeps the doctor away

Proverbial Meaning: Eating apples, and fruit in general, will make you healthy.

Literal Origins: If you eat an apple every day you will not need a visit from your  doctor because you will be healthy.

Common Usage: This proverb was in common use fairly recently, though it is a little old fashioned-sounding these days. One may still see it in print in a school canteen or in a doctor’s waiting room.