Nelson Peltz may have made billions managing hedge fund Trian Partners, but the activist investor is wrong to criticize PepsiCo's management and threaten a proxy fight, CNBC's Jim Cramer said Monday.
After all, Pepsi shares have gained nearly 9 percent year to date, while rival Coca-Cola's stock has lost almost 5 percent over the same time period.
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"I totally appreciate everything Nelson Peltz has done. I've said, if you follow him, you make money," Cramer told "Squawk on the Street." "[But] I would go after Coke. They're the one that is overpaid, fat and happy, doing nothing."
Last month, Peltz told CNBC that Pepsi "is not being managed well," suggesting a proxy contest is likely. On Monday, UBS upgraded Pepsi's stock to "buy" under the premise its management is under pressure.
Read MorePeltz suggests Pepsi proxy fight still on the table
Cramer came to CEO Indra Nooyi's defense, though, crediting her for creating "the best consumer packaged company out there."
"It is time to focus on all the ones that have been losers, not the one that has been a winner," he said. "She's a winner, not a loser."
So who's right about Pepsi? Vote in our poll and comment below!
—By CNBC's Drew Sandholm
Disclosure: When this story was published, Cramer's charitable trust did not own Coca-Cola or PepsiCo.