No, the average spread is probably about the same, heh you don't count on the power of makeup here and also here
More insidious is photoshop check out some before and afters
Some Key points to spotting photoshops are:
Backgrounds ~ if the background is almost radioactive where the photoshop bloke has just used the adjust settings or dodged the photo to hell you know it is a photoshop job, the operators do not have the time to go over each photo carefully to lighten only the model, this is the biggest clue.
Eyes ~ irk the eyes are changed to look cartoon like.
Have a look at this wayy over done one
Urgh I think I just lost my appetite, her face is worse pock marked than mine.
However one thing is that Chinese people are smaller, therefore your average fat Chinese girl is a lot skinnier than a average Caucasian woman.
That is all I can be arsed to write on this topic for now.