You have to pay to read the whole article online, but there's an interesting piece in New Scientist right now about re-creating the conceit behind the movie Super Size Me, in which filmmaker Morgan Spurlock ate nothing but McDonald's for 30 days and documented the effect on his health. The re-creation was done under very controlled scientific conditions in Sweden and had surprising results. The experiment, as I understand it from this Wall Street Journal report and other commentary, used a cross-section of volunteers who all started at roughly the same low weight, had a mechanism to measure/ensure a lack of physical activity, and had the subjects eat a certain (ginormous) number of calories of junk/fast food every day. The result: people gained weight at very different rates--the experiment affected people's health in very different ways, period. Maintaining the same inactivity and eating the same food, some people gained a lot, more than Spurlock, some gained half that, some a little. Changes in cholesterol levels were wildly different too; one subject even came out with a lower reading. This whole thing doesn't surprise me too much, but it's intriguing enough that I'm tempted to pony up the $4.95.