"Baywatch" was known for its red bathing suits and hot bodies, and some life-saving rescues too, but behind the scenes there were weight clauses and drama.

"[There] was a five-pound fluctuation you couldn't go up or down," Nicole Eggert told "Entertainment Tonight," which gathered the show's stars for a 25 th anniversary reunion.

"If you did anything to gain or lose weight, etc., you were in trouble," added Traci Bingham, a cast member from 1996 to 1998.

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Other "Baywatch" stars, including David Hasselhoff, Parker Stevenson, Brande Roderick and David Chokachi, joined Eggert and Bingham in dishing on the show's behind-the-scenes secrets, including the full story on those famous red swimsuits.

"When I auditioned for the show, I was asked to try on a suit and it was Pamela's," Bingham said, referring to the show's headliner, Pamela Anderson, who did not attend the reunion. "I didn't think it would fit, but it did. So, yeah, it was pretty awkward from the beginning."

Eggert, who appeared on the show from 1992 to 1994, told ABC News' Cecilia Vega the "cattiness" among cast members only got worse as the series, and its stars, grew in popularity.

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"It got very competitive as the years went on," she said. "There were more women going for that look and wanting to be the hottest and the sexiest. Just cattiness, you know? Who got more airplay or who booked this magazine [and] who did this photo shoot."

Even though the stars had a clause forcing them to stay slim in their swimsuits, Eggert said it was still a struggle to keep the red suits on because they were so skimpy.

"We had plenty of moments where it didn't really stay on," she said. "Especially the top too because it had a really low back so one little slip and the shoulder came off [and] you know what happens when the shoulder comes off."

"It happened a lot," Eggert said.