Missy Chase Lapine had claimed Jessica Seinfeld copied her secrets on how to get children to eat vegetables.
The New York appeals court said Wednesday that "stockpiling vegetable purees for cover use in children's food is an idea that cannot be copyrighted."
Both books were published in 2007.
Seinfeld's is called "Deceptively Delicious." Lapine's is titled "The Sneaky Chef."
Messages left with lawyers on both sides were not immediately returned.
The 2nd U.S. Circuit Court of Appeals in Manhattan issued its opinion just two days after hearing oral arguments in the trademark infringement dispute.
By Larry Neumeister