Last month we noted that no one (with the exception of animal rights lunatic Neal Barnard) supports legal shark John Banzhaf’s theory that fast food is addictive. Now we know why.

The scientific research on the supposedly addictive nature of food, with which Banzhaf merrily threatens restaurants, was misrepresented. So say the scientists themselves.

According to Obesity Policy Report, Matthew Will, co-author of an unpublished University of Wisconsin study on high-fat diets in rats “was correctly quoted as saying that [his] research ‘suggests that a high-fat diet alters brain biochemistry.'” However, the conclusion

… that fatty foods are addictive — wasn’t even a focus of the study. “We gave rats a chronic diet of a high-fat chocolate drink for two weeks and then looked at their brains afterwards,” Will said. They found that a certain gene in the striatum of the brain was “down-regulated,” or operating at a lower level of activity than it had previously. The same down-regulation was found after rats were given morphine for two weeks, as well.

But a less active brain gene doesn’t necessarily equal addiction, Will stressed.

“Addiction is kind of a vague term, and we obviously can’t say that we’ve proven that you can become addicted to food,” he told OPR. “All we found is that there are similar findings between this high-fat diet we gave the rats and what you see after similar schedules of morphine in rats.

“We have no idea what it does to their behavior necessarily,” he added. “We’re exploring that in the future. All we have right now are the parallel changes in the biochemistry.”

Obesity Policy Report also quotes a spokesperson for Rockefeller University saying news stories have “exaggerated the research being done by our scientists” which “has nothing to do with addiction.” That means (at least) two of only four studies described in the New Scientist article Banzhaf brandishes as a weapon have been habitually distorted.

All this talk of “changes in biochemistry” may sound a bit frightening, but remember that everything from sleeping to running will affect the brain in some way. Even “opioids” — a chemical that sounds disturbingly like it has something to do with illegal drugs — are simply the natural byproduct of everyday activities like exercising.