More than a century after President Theodore Roosevelt signed the Pure Food and Drug Act, deception is still a far too popular marketing tool for food makers.

The Federal Trade Commission barred Kellogg’s last year from running ads saying Mini-Wheats are “clinically shown to improve kids’ attentiveness by 20 percent.” To claim “benefits to cognitive health, process or function provided by any cereal or any morning food or snack food,” was a no-no, unless the claims were true. But the F.T.C.’s order covered only cognitive abilities. So just as it was signing its consent, Kellogg’s was starting a new campaign in which “Snap, Crackle and Pop” called out to parents from the Rice Krispies box promising to help “support your child’s IMMUNITY.”

Last week, the F.T.C. said that it had closed that loophole, reaching an agreement with Kellogg’s that would bar the company from making any claims about the health benefits of their food unless they were backed by scientific evidence and not misleading.

Businesses have been making dubious claims about their products at least since the 17th century, when the British clergyman Anthony Daffy sold Daffy’s Elixir as a cure for scurvy as well as agues, gout, rheumatism, rickets, worms and other ailments. Hucksterism  no matter how implausible the claim  lives on.