Dr. Ruth Westheimer, who is probably the only person in the country who could tell a roomful of professionals about the joy of onion rings in bed, devoted an hour yesterday to the nation's august newspaper editors.

And even at 9 a.m., the room was packed.

The usual mainstays of the American Society of Newspaper Editors' conventions have been such subjects as color on the front page, or how to lure advertisers, or libel laws or ethics.

The topic yesterday was "What Editors Should Know About Sex." And the participants included not only the diminutive queen of sex-news, Dr. Ruth, but also Shere Hite, who has been researching sex for more than a dozen years and who has put out the bestselling "The Hite Report" to give readers her findings.

"I'd like to congratulate you for a record turnout for our business meeting," moderator Robert Stiff, executive editor of the Tallahassee (Fla.) Democrat, said as he opened the session -- a session that would be punctuated over the next hour by more than a few embarrassed giggles.

Explaining that he had heard a lot of bad jokes about why he was picked for the job, Stiff then said he had a bad cold and told the president of ASNE that he had a viral problem. "He misunderstood me and thought I had a virile problem," Stiff said.

With that, about 600 people settled down to what eventually became a somewhat serious -- but not overwhelmingly serious -- discussion about how much sex should be allowed in the nation's news journals.

Not unexpectedly, Dr. Ruth made a pitch for helping create a "sexually literate society," adding, "We can send a man to the moon, but we cannot prevent 1.5 million unwanted pregnancies each year."

Hite, who said newspaper reporters either report about sex clinically or use these stories to provide a little titillation, held up a USA Today headline that said "Dolly Parton Gets in Shape," which, of course, drew embarrassed giggles.

Dr. Ruth, who was also there to peddle her column for King Features, had a hard time persuading at least one participant that her column was less entertainment and more serious discussion about the responsibilities of sex.

"I wonder if we owe our readers this?" said Jim Jacobson, editor of The Birmingham (Ala.) News.

"If we can help them with good shopping, why not help them with good sex . . . ? I say no. I think the subject needs to be taken seriously and not turned into a dirty joke or the equivalent of a plumbing manual," he said.

Jacobson said he dropped Dr. Ruth's column and allowed his competition, the Birmingham Post-Herald, to pick it up. He added that he does not allow X-rated movie ads, which he said his competition also prints.

"The other paper sounds like more fun in Birmingham," said Stiff.

Then there was also the opposing view. Arnold Friedman, editor of the Springfield (Mass.) Union-News Republican, complained that Dr. Ruth seemed to be writing too much about the responsibility necessary in sexual relationships.

"I, for one, would like to see it deal more with sex than it has and take the flak that goes with it," Friedman said.

Some editors were concerned about the appropriate age for youngsters to hear or read Dr. Ruth, but there were no easy answers. Some are not ready for her advice when they're as old as 25, she confessed. And she said that many 14-year-olds agree to go to bed early on Sunday night so they can slip on earphones and listen to her radio show under the covers.

"I hope after a few times they get bored. There is not an infinite variety," she said, adding that she hopes at least they get some "truth" as an antidote to what their peers are telling them.

Hite and Westheimer both talked about the importance of telling the truth in talking about sex to kids and stressed that most youngsters are exposed to sex in films or pornography at an early age.

"There are very few teen-agers left who haven't seen [pornography] by the time they are 9," said Hite. "That's why it's good to have counterinformation available."

With that, the hour was over and the newspaper editors, here for their 86th annual convention, went on to more serious matters. At least, some of them went on to other matters. Within minutes after Dr. Ruth left and the session turned to the question of changing the bylaws of ASNE, the audience dwindled to about 250 -- 300 max.

It was a tough act to follow.