"We were surprised by the frequency of obesity among the severe cases that we've been tracking," said Anne Schuchat, one of the CDC epidemiologists managing the outbreak. She said scientists are "looking into" the possibility that obese people should be at the head of the line along with other high-risk groups if a swine flu vaccine becomes available.
And it is entirely possible that there's something to that, though the article gives us no direct evidence to support it.
But if any such evidence exists, it certainly isn't to be found anywhere in the MMWR paper. And the paper's authors make no claim that it is, so don't blame them for the inaccuracy.