So then why does Snake look younger than 50 in four different Metal Gear games?

Genes don't work like that.  Your basic genetic code should stay the same throughout your life, and it is ultimately cell division that causes things to go wrong after a time (due to cells not dividing correctly, cells mutating, etc.).

Advanced cellular degeneration caused by the cloning process used to create him has aged him prematurely. That is how things work. Ever keep hearing the phrase you havn't aged well? It was used even in metal gear solid 1 by frank jaeger. I also know im correct cause I was asked this question at the midnight launch and won a playstation backpack for it.

here we go some more proof to show im right, its staight in the second paragraph

http://metalgear.wikia.com/wiki/Solid_Snake

At bolded: That is how things work where? You're acting like this is scientific fact.

Also your first statement about cellular degeneration caused by the cloning process aging him prematurely contradicts your earlier statement that it was caused because he has the genes of a 50 year old man. Also Snake is in his fourties in MGS4 based on the timeline(born in 1972) meaning he's over 90 years old when you add that 50 years he started out with. I fail to see how Snake would have been able to do anything other than walk to the nursing home with a cane at that age.

Do you ever wonder why you never hear of clones living long for animals and usually die within a few years? It is because of this.

Here is a link even proving that

http://www.associatedcontent.com/article/353417/is_cloning_safe.html

he primary theory as to why Dolly and other clones did not survive is that of accelerated aging. Accelerated aging in this sense would be due to the shortening of telomeres. Telomeres are "the segment of DNA that occurs at the ends of chromosomes (Cloning)." These segments prevent genetic threads on the DNA from wearing out. Once these telomeres are completely worn out, the DNA can no longer be reproduced.

EDIT: and once again in case you missed it. The history of solid snake stating exactly as i have said above. http://metalgear.wikia.com/wiki/Solid_Snake

I'll answer the third one, from what I know about it.

Snake was designed to die at an early age, because he was only needed temporarily, and they didn't want him getting out of control.
FOXDIE was injected in him not to kill him, but to kill the deserting Patriots. At least, that's what Drebin's FOXDIE was for.

So then why did you say it had to do with him being cloned from a 50 year old man(Big Boss). That isn't supported by the links you've provided at all. This telomeres theory doesn't indicate the results would be any different no matter what the age of the cloned animal would have been whether it were a child or adult. You implied originally that it was caused by Big Boss' age at the time of cloning which means the results would have been different had Big Boss been cloned as a child instead. However your links do not support that.

I also have a link from the Human Genome Project that states clones have also been perfectly healthy and died mysteriously. One such animal from Australia had no known cause of death on it's autopsy. I don't see where accelerated age comes in there.

Gah most of this cloning stuff brings up results to rapid aging of clone troopers lol, but i could have sworn I saw a cutscene in one of the metal gears saying that since they cloned an old man they're gonna age faster as well. I even heard this somewhere outside of the MGS series. I'll find a link other then starwars that supports it sometime later :P

Fow now I will bow down to the "age factor" but I did clear up that it was not foxdie (which i kept reading over and over again, which wasn't true.) and it is the fact that he is a clone which caused the aging.

@Onyx: As cloning is a word used to describe processes used to duplicate something. When you duplicate aged cells, the duplicated cell is an aged cell to begin with (how else can you clone something). This isn't limited only to cloning, also the age of a mother (giving birth) effects the daugters ability to reproduce, since the reproductionary cells are "cloned" from mother to daughter. And as we live, old cells die in any case and new ones grow, but the new cells that replace the old ones, are already "old" (if not, everyone would be young forever).

In order to make a "new" clone, the cells would need to be altered as "new" cells, instead of growing a bunch of old cells (as it currently works).

If we think at the theoretical example of cloning a human (growing a human out of cloned cells, as how the process would work), the infant would grow normally, with the difference that the cells would deteriate fast and at a relatively young age, not that the clone would be born as 20 years or 50 years old.