Quote Originally Posted by ysc1230 View Post
Thank all teachers.

In my mind, as reported speech is used to reporting someone conversation, then I need not consider whether the statement is still true.

Therefore, I think I should report the statement to others by using past tense.

1. Mary said "I am fat". ->> Mary said she was fat.
I agree. Backshifting will always (fingers crossed!) be right, so it's less confusing simply to always do it.
To me, "Mary said she is fat." is an unlikely sentence in real life.