The Super Size me man was medically supervised throughout.
But again, rereading the original article, I couldn't quite see what he author was getting at. He didn't seem to be advocating a fast food diet. A burger is nutricious but doesn't provide the full range of nutrients, and he doesn't say it does, but he then compares it with with buying top of the range full spectrum of nutrients food, which is comparing a car with a lorry. And as the 'thegirlcalled jack' website I quote above shows you can feed yourself and a child nutritionally for a week, all meals, for less than the price of one burger a day, let alone one each.