I disagree that Wall-E makes a connection between obesity and environmental issues. The film clearly indicates that the "loss of bone mass" occurred because of space travel, and the availability of hoverchairs (originally for the elderly). The environment was a mess before humans left Earth, and the obesity occurred after, and partly becuase of, leaving Earth.

I do appreciate the article addressing the fact that "other critics" tend to link the two, and that these links are unfounded.