The FDA says Cheerios is being marketed a drug? That’s totally ridiculous. The FDA may have evidence that some of General Mills’ claims are exaggerations. I don’t know. But who do they think they are declaring Cheerios a drug?
They have the definition of "drug" in the Federal Food Drug and Cosmetic act, which includes any substance "intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease in man or other animals." Intent, for the purposes of the statute, is determined primarily by looking at the claims made by the manufacturer.
This is really nothing new, and it happens all the time (the only strange thing here is that it got some press coverage) - for decades (perhaps even as far back as 1938, when the FDCA was originally enacted), there have been battles between the FDA and food manufacturers over what sorts of claims food manufacturers can make without manifesting an "intent" to treat/cure/prevent disease. It is not at all uncommon for the FDA to reject particular language, and for the company to negotiate with FDA to reach an amicable solution. That seems to be what's happening here, and, again, the only odd thing is that this has gotten press coverage.