george orwell (who also wrote 1984) conducted a similar experiment in the late 1920s and wrote a book about it:
http://en.wikipedia.org/wiki/Down_and_Out_in_Paris_and_Londo...
http://en.wikipedia.org/wiki/Down_and_Out_in_Paris_and_Londo...
http://books.google.com/books?id=WREtVBBT9lEC&lpg=PA1... (changed link to Google books; removed short link)
I don't know (and don't much care) what Tyra Banks did and I need to read the blogger more fully (I've only skimmed it), but Orwell spent years of his life (at different times) investigating poverty. The simulated or forced poverty he underwent in England was measured in months, not days or weeks (in 1927 and 1928). He also explicitly discussed (and agonized over) how "real" his poverty was given that he could wire home for money (and sometimes did, as I recall). I think that simulation can only go so far, but not all simulations are equal.