One could use "we" in that sentence, but I have no problem with "ourselves".
Many people lack a clear image of their bodies, and do not take ver good care of themselves. You'd think people would have a fairly accurate picture of their own bodies. After all who is more familiar with our bodies than ourselves?
The first reflexive pronoun is thought to be properly used, for subject and object are the same people.
The second reflexive pronoun is in question, in fact.
Personally, it is quite familiar use, but what I am wondering is whether the subject and the object are same.
So is this usage correct or acceptable?
What you will hear more often is "Who is more familiar with our bodies than us?"
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.