Talking about his new book, "Fast Food Nation: The Dark Side of the All-American Meal," Eric Schlosser recently tossed out the overused claim that "the cost of obesity is 300,000 people a year." (You’ll need Realplayer to listen to this clip. Get it here.)

But is it? Or is that number inflated by the influence of the weight-loss industry and anti-choice activists like the Center for Science in the Public Interest (CSPI)?

The 300,000 figure comes from an October 1999 study that appeared in The Journal of the American Medical Association. Two of the five authors of that study were Dr. D.B. Allison and JoAnn E. Manson.

Allison, who, in voicing support for an onerous and unnecessary "Twinkie Tax," told the San Diego Union-Tribune in 1994 that it might somehow be a good idea to "have higher taxes on Ho-Hos and lower taxes on bean sprouts," has numerous ties to the weight-loss industry. The study’s financial disclosure notes, "Dr. Allison has received grants, honoraria, monetary and product donations, was a consultant to, and had contracts or other commitments with numerous organizations involving weight control products and services."

Manson (a CSPI board of scientific advisers member) has already gotten into trouble once for a conflict of interest on a related matter. In 1996, Manson wrote an article for the New England Journal of Medicine hailing the benefits of the weight loss drug Redux without disclosing she had been a paid consultant to the company which produced the drug. ("Flap over NEJM editorial on weight-loss drug brings heavy news coverage," Medical Marketing & Media, October 1996)

Knowing what we do about the conflict of interest involved here, can we put any trust in Allison and Manson’s conclusions?