These lists are insane. The factors they're choosing must be distorting them. Any list that has St. Louis and Milwaukee under "fittest" and New York under "fattest" is cooking the books.
Here's a chart on wikipedia that lists it by state.
http://en.wikipedia.org/wiki/Obesity_in_the_United_StatesThat's not completely helpful for correlations to cities, however, they have identified trends with mass transit use (inverse) and income (also inverse) while some of the other factors that Men's Health have used (air quality?) do not correlate at all with "fatness."
