The soft drink giant, along with others in the sector, has taken incoming fire from nutrition advocates concerned about the health impact of sugary drinks and fatty foods. Notably, an effort to ban soft drinks of a certain size in New York City failed in 2014, after a state court declined to renew the limit instituted by former NYC Mayor Mike Bloomberg.
"We ought to have a law ... where these people shouldn't be allowed to cite the defects without citing the advantage. It's immature and stupid," Munger said Saturday at Berkshire's annual shareholders meeting.
Berkshire has been a longtime shareholder of Coca-Cola and owns 9.2 percent of the Dow component, according to a 13-F filing from Dec. 31.
Buffett, Berkshire's chairman and CEO, also defended the Coca-Cola stake Saturday, saying it seemed "spurious" to argue that calories from Coke alone were a significant factor in obesity levels.
He also noted that he consumes approximately 700 calories of Coke every day, and that he had seen no evidence that switching to "water and broccoli" would make it easier for him to make it to age 100.
"I'm about one-quarter Coca-Cola," he said. "I elect to get my 2,600 or 2,700 calories a day from things that make me feel good when I eat them. That's my sole test," he said. "I like fudge a lot. Peanut brittle. I am a very, very, very happy guy."
— Reuters contributed to this report.