What is the origin of the idiom "close to the bone" and when to use it?

The idiom "close to the bone" likely originates from the idea that when something is close to the bone, it is very near the core or essence of a matter. The bone is often associated with the central and essential part of something. In this context, it suggests that the statement or description is touching upon a truth that is at the heart of the matter, and it may not be sugar-coated or softened. It is commonly used in conversation and writing to describe something that is candid, honest, or uncomfortably close to reality.