For example.
I used to be able to go into topshop and fit into clothes. No more.
I used to be a size 10 to 12. Now I'm lucky if I can squeeze into an 18.
I am the same, i am sure.
I believe that actually sizes and much smaller and what was a size 12, 20 years ago is now 5 sizes smaller.
This would also account for slebs being size zero. In my day there was no such size available - Look at 'Pretty Woman', for example, 22 years ago Julia Roberts was a size 6 (American size so Equivelant British size 10). Would she be a size 10 now? Or would the lady in the shop say 'you're a zero right?'
AIU? I think not.