The first question people generally ask me about all this is "Why?" Actually, it's usually more along the lines of "Why in God's name would you want to do that?" or "What the hell is wrong with you?" The short answer is "Because it's there." The long answer is, quite naturally, longer.
The main response I have is simply "Why not?" I mean, most of us have pets, and most of those pets eat exactly the same thing every day. And, since those foods are specifically formulated for that animal's nutritional needs, most pets eat much better than their owners. Or, at least, eat much healthier.
So, what if we (humans) did the same thing? Why isn't there a "human chow?" At the very least, it could be a low-cost food for the poor or the college-inclined. It also could have applications as survival rations or disaster-relief supplies. The Angry Man suggested using it in prisons, which isn't a bad idea either.
Of course, the main objection one has is that food is one of life's pleasures, and to reduce our diet to kibble takes away part of our joy. I agree wholeheartedly, as I pride myself as being a bit of a glutton (hence the 30 pounds mentioned in the introduction), but imagine if you ate monkey chow (or human chow) most of the time. You could eat whatever you wanted the rest of the time. Since you would be getting all of your nutrients from the chow, you could have a huge, hot fudge sundae every day and not worry about it at all. You could have lunch at McDonald's...well, I guess you'd probably still want to avoid McDonald's. But the point is that you wouldn't have to worry about eating a balanced diet or taking a vitamin pill everyday, as you would be getting everything you needed from the chow.
So that's it in a nutshell. I know it probably still seems loony to most people, but in the end, I'm doing it for the fans. :)