OK, let’s say I’m suicidal. However, I don’t have access to a gun, and I’m too scared of heights to jump off a tall building. Also, good poisons are hard to come by, and there are no suitable trees in the area to hang myself from. Additionally, I’m a lazy bastard. Would it be possible for me to simply plop down on my couch, put on a movie for entertainment, and simply stop taking in any food or water? How long would it take for me to die? What would the experience be like? Would a “survival instinct” kick in at some point, and implore me, in spite of myself, to go to the kitchen and get a sandwich and some coffee?
As far as dehydration goes, it’d be quicker but probably harder to pull off. I’ve heard of terminally ill people refusing hydration but not otherwise healthy people. Apparently being severely dehydrated is more unpleasant than merely being malnourished.
I’ve heard of several instances of suicide by starvation by prisoners, usually as a form of political protest. Bobby Sands, of the Irish Republican Army, took 66 days to die from starvation.