Coming in a little late to the discussion. Sorry!
I have to feel like this is a bit of a trick-question. After all, if I chose obesity again over diabetes, heart disease, amputation, etc. It seems to me that obesity itself will increase the risk of all of these ailments/outcomes! And yes the question is in dire need of some more solid parameters. Is the hypothetical obesity permanent, or can I try and lose it again?!
I think another very important question to ask about studies these days is: Who paid for them? Seems like there's a lot of shady data floating around these days. Especially when it comes to pharmaceuticals.