This is mentioned in the article, as well of some possible explanations why replication was not possible. My personal favorite is:

"The University of Wisconsin’s control monkeys were allowed to eat as much as they wanted and were fatter than those in the aging institute’s study, which were fed in amounts that were considered enough to maintain a healthy weight but were not unlimited."

This would seen to suggest that although caloric restriction may not prolong life, an all-you-can-eat diet may shorten it.

    > This would seen to suggest that although 
    > caloric restriction may not prolong life, an
    > all-you-can-eat diet may shorten it.

This is basically what I came to post. A calorie restricted diet may not prolong life compared to a healthy, normal weight, but obesity certainly cuts lifespan short through a plethora of health issues.

Yes it can cause all kinds of health problems, but the actual decrease in average age for a moderately obese person is only about 3 years.

Yes. Derek Lowe discussed the articles, and I made almost your exact point in the comments there.

http://pipeline.corante.com/archives/2012/08/29/caloric_rest...