"I think there's big opportunity for Herbalife," he said on CNBC's "Squawk Box" on Wednesday, when asked about the multilevel-marketing nutrition company.
Siding with activist investor Carl Icahn over hedge fund manager Bill Ackman, Simon said, "One thing Carl did say in his [CNBC] interview last week, there's a lot of opportunities for weight loss and [fighting] obesity in third world countries."
The Hain chief executive cited that as a reason for his optimism concerning Herbalife. "Eating healthy is not a fad, not a trend. It's going to be a bigger part of [living]," he said.
Last week, Icahn disclosed a 12.98 percent stake in Herbalife, and Ackman responded by saying, it didn't change his short position.
(Read More: Ackman: Herbalife Short Unaffected by Icahn Stake)
Meanwhile, Herbalife reported better-than-expected earnings after the closing bell on Wall Street Tuesday and raised its 2013 earnings projections.
It also revealed in a regulatory filing that the staff of the U.S. Securities and Exchange Commission Division of Enforcement has been inquiring about the company's operations since December — the month Ackman disclosed a $1 billion bet against the stock and called Herbalife an illegal pyramid scheme.
The company has repeatedly denied those allegations, and said it would fully cooperate with regulators.
Ackman's fight with Icahn over Herbalife exploded publicly on CNBC last month, when they both called into "Fast Money Halftime Report" and traded allegations, insults, and counter-allegations.
(Flashback: Icahn, Ackman in Epic Showdown of Billionaires)
A big third player in this stock drama, hedge fund manager Dan Loeb, has sold part of his long position in Herbalife, a source told CNBC. But Loeb's Third Point does maintain a stake, the source said.
(Read More: Hedge Fund Manager Loeb Trims Position in Herbalife)