Oh, yes, dear 50Cent was mentioned here already. I believe he was replaced too. Not only that "he" (?50Cent) lost so much weight, but in a short span of time I saw him at a gala or smth and he was looking like nothing happened: no weight loss, nothing... When the hell did he have time to get back to normal?
Now THAT is freaky! You're right, no way he could go back to normal so quickly. With that level of extreme diet modification/starvation it's unlikely he would ever return to "normal", certainly not quickly.
This brings up another thought I've had about actresses who supposedly lose their pregnancy weight extremely fast. So many stories where the actress is doing a magazine cover literally six weeks after giving birth and looks skinnier than she did pre-pregnancy. With the editorial lead time on magazines (about six months in advance for monthly mags,) it's likely that these pics are actually stock photos taken long before the actress was showing in the pregnancy. But another thought I had was doubles. With Photoshop thrown in the mix, Angelina Jolie or whomever could easily have their film double do these photo shoots. (Of course, Jolie is a whole other can of worms, I'm just using her as an example of a periodically pregnant celeb.)
On every film set the principal actors have doubles that are used to adjust the lighting for each shot of the film. These people have to look a LOT like the original actor or actress. These people are SAG members (or AFTRA for TV) and make a lot money going out to every film set that famous actor or actress performs on, doing all the lighting set ups so the celeb doesn't have to stand there for hours while they adjust the set and the lighting.
Some of these doubles could EASILY pass as the originals. A friend of mine worked with a young Tom Hanks on the movie THe Man with One Red Shoe and said the lighting double looked "more like Tom Hanks than Tom Hanks did." He was apparently a dead ringer for him.
To what extent could these lighting doubles be used as replacements? Like in the case of Britney Spears or someone who has tons of crazy fans and paparazzi following around all the time, these doubles would get a lot of work faking people out by leaving in a different car, by a different exit, to confuse those crazed followers and give the original celeb a bit of privacy and piece. (Again, she's probably Fritney now, but you get the idea.) These very close look-alikes could be used in many situations, not just on sets where lighting is being adjusted.
The use of lighting doubles in TV isn't quite as prevalent. I've seen doubles that didn't really look very much like the originals being used. But in film, the lighting stand-in ALWAYS looks very close to the original. They make them up in the same costume, they have the same skin coloring/tone (very important especially with biracial stars like Halle Berry who have a unique coloration to their skin and have unique lighting needs.) From a very close distance of a few feet you wouldn't know they weren't the originals.
So.....I just wanted to talk about these stand-ins, how every major celebrity has longtime stand-ins who double for them in films, often on every film they do, and how easily someone like that could be tapped to be a replacement on a more permanent basis, or at the very least, a decoy or occasional double for public events, etc. Many of them these days have plastic surgery to look like the stars, too.
And some of them might be used in these photo shoots where a pregnant celeb suddenly drops 40 pounds post-pregnancy in just a couple of weeks. It's so important to always look thin in photos, an actress can lose important jobs just because she looks a little bloated in a photograph. I doubt that control freaks like the Jolie/Pitt machine would ever allow an unflattering photo to be taken, so they could use a lot of doubles for such photo shoots.
Also I wanted to mention how all actresses and models are forced to have chronic eating disorders and starve themselves constantly to remain thin - plus cocaine and diet aids like very expensive diet drugs from Europe help. So I'm not convinced many of them can conceive naturally, anyway, with the career-long abuse that they do to their bodies.
Just to clarify, I am a SAG/AFTRA member and have worked as a standin
and worked with many, many other standins in features and television
over the years. This includes productions from all the major studios and
networks.
There are 2 jobs in the movie business that often get confused. One is
standin and the other is a photo double (or stunt double or body double).
A standin is never photographed and works only between takes during shot
setups and sometimes tech rehearsals. Standins are actually considered
crew and work for the Director of Photography though they are members
of the the actors unions as they are sometimes called upon to perform in
some way during rehearsals.
Photo doubles
are photographed and must resemble the actor but
almost never the face. Photo doubles are almost always shot in such a way
that the face is not visible or too far away for recognition.
A few standins do look remarkably like the actor they stand in for but
the majority do not particularly. I don't recall ever seeing Tom Hanks'
standin so he may well well be one of these few but this is not usual.
The most important qualification is that the standin be the same height.
This is what they are most concerned about for framing purposes. After that
it's preferred that they have similar coloration and build but there is a lot of
leeway on this, at least in Hollywood.
I've seen many times where a standin will be given super-tall shoes and
a wig to match the height and hair of the actor while looking nothing
like him/her otherwise. It's also not unusual for standins to have signs
hanging around their necks with the name of the actor they represent to
avoid confusion. Little people also work as standins for child actors who
they don't resemble at all except for height.
Females sometimes stand in for males and vice versa at times and I once
stood in for an Asian actor (I am caucasion) on a Disney picture, much to
the amusement of a group of Asian female extras playing hookers in the scene
with me. In all my standin jobs I was only required to be the same height and
general color/build of the actor.
I worked in a scene (as a extra) in War of the Worlds that took 3 days to shoot.
A scene with Fom Fruise where I worked very closely with his stand in (and Fom too)
and the standin looked nothing like him except he was the same size and coloration.
Dakota Fanning's standin on that picture was an adult male little person with dark
features who wore a blond wig and who looked nothing like her except from behind.
I've also worked in many other scenes with A-list celebs and their standins
and never saw one that would really pass for the real actor but a few did
look quite a bit like them such as Julia Louis-Dreyfus's standin and a few
others.
I'm not saying that lookalikes don't exist (they definitely do) but they don't
normally work as standins as a normal thing during normal production.
There are just too many people around. That is how it works in Hollywood
production anyway. It may well be different with still photo shoots and
other special circumstances where there aren't a lot of cast & crew around.
Now, photo doubles are used for scenes where the actor's character is
shown at a distance, or driving by in a car, etc. They are too far away to be
completely recognizable. If a close up of the actor's body is needed then
the photo double is used and referred to as a body double. This might be
where close-ups of hands or back of head or nude scenes, etc. If stunts
are required then a stunt person who also looks like the actor is used, called
a stunt double but, again, the face is never shown in a recognizable way.
Sometimes they even wear masks such as in stunt sequences or they can now
add a face digitally to a stunt double's body. I once worked in a fight scene
with Nicolas Cage's stunt double who looked exactly like Nic but only from the
rear. His face was no match at all. This is the norm.