Furthermore, the vanadium study cited in the book's appendix examined subjects who took the nutrient in amounts 750 times greater than what Dr. Phil suggests. "Ten [micrograms] is a laughable amount," said Almada.
Dr. David Heber, director of the UCLA Center for Human Nutrition, criticized Dr. Phil's nutritional supplement information as well. Dividing people into "apple" and "pear" body types, as Dr. Phil has done in his book and with his supplements, is essentially meaningless, he said. "There's no difference in the supplemental needs between an 'apple' and a 'pear,' " he said. "There's not a lot of science to support what he's saying on that point."
As for Dr. Phil's nutrition bars?
"You can get the same thing at Trader Joe's," added Heber. "A bar is a bar is a bar."
The challenges, however, are unlikely to derail Dr. Phil, who has consistently touted the scientific accuracy of his book. As for the nutritional products, "I think it's a good product and I'm doing it for a really good reason and purpose," he told the New York Times in a recent interview. "Although if I was doing it for a commercial -- as a brand extension of my own -- I wouldn't apologize for that either."
But even if he is capitalizing on his fame, as some observers contend, in the end, his contribution to battling America's considerable weight problem may be more important.
"Overall his message is pretty healthy," Thompson said. "Someone needs to be saying it."