Nutrition studies will often use people as their own controls because of the significant variability between people. Nobody is willing to fund nutrition research with "perfect" studies, so researchers do what they can (especially when they are known to have hypotheses counter to the orthodox view).
On their books, I think that would be a ridiculous thing to reject people's findings for. Almost every academic has written a book at some time. Instead, we need to recognize the possibility of a bias inherent in every researcher and look to the study design, execution, and conclusions to see if they hold. Phinney and Volek are in a different class when it comes to their books and their ideas than is, say, Robert Lustig.
On their books, I think that would be a ridiculous thing to reject people's findings for. Almost every academic has written a book at some time. Instead, we need to recognize the possibility of a bias inherent in every researcher and look to the study design, execution, and conclusions to see if they hold. Phinney and Volek are in a different class when it comes to their books and their ideas than is, say, Robert Lustig.