The genitive of 'one' (used instead of 'you') in formal contexts?

Question

It's better to use 'one' instead of 'you' in formal writing but what about the genitive of 'one'? your body => one's body/ ones body / ...? What is correct?

Answer 1

It's all about context. The genitive case shows possession, but can also denote origin, source, or a characteristic or trait. Formality or not is not the only consideration

Examples:

"To lift one's body with balance beams is difficult" is certainly the more formal expression appropriate for writing. However,

"Jack is strong enough to lift your body with one hand." One's body has a different meaning.

Answer 2

The possessive form of "one" in English is "one's."

You may write, "It's essential to take care of one's body to live a long, healthy life."

"One's" can seem very formal, but it is correct. For a slightly less formal situation, it's also appropriate to write something like, "People must care for their bodies if they want to live long, healthy lives."