Katz also discussed his ONQI system on Marion Nestle's blog, What to Eat. Nestle is not a big fan of such systems. I found this part of Katz's response badly insufficient:
As for the concern raised about the system being proprietary: the ONQI was developed with no commercial interest in view. It was supported by the non-profit Griffin Hospital, in Derby, CT- and when finished, offered first to the US FDA. The FDA, while very supportive of the work and the sophistication of the ONQI, encouraged commercialization as the only way to get the ONQI into consumer hands any time soon.
So now, yes, there are business interests involved. And there is intellectual property. But the fundamental workings of the ONQI algorithm were shared with scientists at a conference held in Washington, DC on 11/30/07 devoted to the purpose of transparency. Dr. Nestle was invited, but unable to attend. The ONQI will soon be published in the peer-reviewed literature as well. Not every last detail of the algorithm will be shared, but more than enough for those even with somewhat less expertise than Dr. Nestle to judge the reliability and robustness of the system. Of the 100 or so scientists who attended the November conference, not a one complained that they had insufficient detail to judge the algorithm.
I won't trust any food rating system whose full scoring details can't be widely shared with everybody and scrutinized. A conference presentation or partial write-up does not suffice.