A Conspiracy of Hogs: The McRib as Arbitrage | The Awl.
Great analysis.
http://www.fivethirtyeight.com/2010/04/double-down-by-numbers-unhealthiest.html
Nate’s nutritional basis for his statistics may be in question, but the quality of the comments is worth the price of admission. I have had a similar idea of such an index or value, similar to the NuVal system the Hy-Vee uses.