PET Theory

Jacob Sullum | May 7, 2004

In this morning's press release, the tireless litigation (and self) promoter John Banzhaf--who yesterday was kvelling over Morgan Spurlock's movie Super Size Me, bragging that he "helped develop its major premise"--calls attention to a study he says provides "new evidence some fattening foods may be addictive," an argument he thinks can be a winner in lawsuits against fast food companies. Reuters reports that "the researchers scanned the brains of normal, hungry people and found their brains lit up when they saw and smelled their favorite foods, in much the same way as the brains of cocaine addicts when they think about their next snort."

There are two major problems with using such evidence to recover damages from McDonald's, Burger King, or Pizza Hut. First, there's no reason to think their food is harder to resist than homemade versions of the same dishes. Second, cues for all sorts of pleasures elicit detectable changes in the brain. As the psychiatrist Sally Satel noted at a conference on obesity last year, brain images “cannot distinguish between an irresistible impulse and an impulse that is not resisted.” Instead of showing that the urge for a cheeseburger is overwhelming, this sort of comparison suggests that the urge for a snort of cocaine is not as powerful as the government would have us believe.