Shrinking Celebs

What is the deal with these female celebs (and some men) who appear to be thinner every time you see them? It's weird. I first noticed it with Sarah Michelle Gellar, years and years ago, then I saw it in Lindsay Lohan ... and Ryan Seacrest.... The list goes on and on....
I don't notice it as much with Black, Latino or Asian celebs, but we don't really get to see much of them to begin with. Maybe the Lollipop-Head thing is only big in White Hollywood.