Sarah, Duchess of York, was on the road again, and feeling vaguely gloomy. She sent her driver into a deli to buy her two cheese and tomato sandwiches slathered with salty butter and two "full-bodied" Coca Colas, none of that diet stuff. The driver, aware of the Duchess' role as a Weight Watchers spokeswoman, asked if she was sure. She insisted.

But before chowing down, she called her Weight Watchers adviser on the cell phone and, sounding like someone hoping to be talked off a ledge, told her she was about to gobble it up.

"What are you feeling sad about?" her adviser asked.

At first the duchess couldn't put her finger on it, but then her buried emotion surfaced and she realized how loath she was to leave her daughters, her little princesses, behind yet again. Eating those yummy sandwiches would have "compensated for that great sadness." Ultimately she resisted the sandwich, but was able to cry. Tapping into her feelings was an extraordinary experience for the duchess, who had buried her woe in food since she was a girl.

Yesterday, the duchess told the story to a group of 350 Weight Watchers members, a lucky few who had been plucked from 10,000 lottery entrants to attend a "Super Meeting" at the Sheraton Baltimore North. Nearly all women, they came from Joppatown and Annapolis, from Perry Hall and Glen Burnie. Here and there among the middle-aged women was a school girl or a young mother who had left the baby with Dad to attend.

Subdued, a tad wan from her trans-Atlantic flight that morning, Sarah Margaret Ferguson entered the meeting amid a throng of beach ball-tossing Weight Watchers bopping to the event's summer's-nigh, lose-that-weight theme. Plucky "Fergie" warmed to the task as she tossed her notes and for 10 minutes spoke extemporaneously about how Weight Watchers has changed her life.

"I'm talking from the heart about a subject that's going to save my life. About truth," she said. "Since I was 12, I've had a problem with my weight," she confided. That was when her mother left her and moved to Argentina with her new love, a polo player. "I ate and I ate and I ate," the duchess said. "And I ran away from my feelings."

The duchess lauded three members selected to come on stage and tell their success stories. "Let's see your pants," she said to Charles Shird, a 46-year-old man from Reisterstown who had dropped 86 pounds and had the cast-off duds to prove it. The crowd giggled at her bawdy quip.

"You look amazing!" she told all three. "Congratulations! Well done!" she said, as if they had medaled in dressage.

She talked about how gaining control over her appetite has made her a better mother and friend, although she admitted there are still days "when I'm completely out of control." She discussed the pain of being called the "Duchess of Pork" in the British tabloids and said that she has now learned to be happy with a couple bites of a favorite, fattening food.

"If I can do it, you can do it. Let me tell you!" the duchess exclaimed.

Audience members, brandishing cameras, were delighted to have royalty in their midst, even -- perhaps especially -- someone who had publicly made a royal mess of her life.

For her fans, Fergie's energy, zest and gutsiness have more than made up for her public gaffes, compulsive shopping habit and yo-yoing weight, which topped 210 pounds at one point. Her fetching imperfection has made her the working girl's princess, champion of endomorphs, the self-conscious and misfits of the world.

This is no sullen supermodel vamping in a bikini. It's a frazzled working mom who said her campaign to lose weight got a big boost when her children said to her: "Mummy, can you do your wobbly bottom for us?"

Ruth and Donald Goldbloom drove in from Grantsville in western Maryland for yesterday's event. Ruth, 45, has shed 230 pounds, with 40 more to go; her husband has lost 90, meeting his goal. The duchess was "inspiring," she said. "It's absolutely neat to seem someone one [who is] royalty, God bless them, who has been where I have been, who every day goes where I'm going."

The duchess signed on as a Weight Watchers spokeswoman in 1997 for approximately $1.7 million, a fee that has helped her climb out of enormous debt. She appears on television ads and has authored two Weight Watcher cookbooks, "Dining with the Duchess" and "Dieting with the Duchess."

Her name, and the company's new 1-2-3 Success Plan, which assigns points to foods based on fat, fiber and calorie content, have been credited with Weight Watchers' rebirth and soaring enrollment, projected to hit 30 million this month.

The duchess must be doing a good job. The same cheeky irreverence that once got her in trouble is now a selling point with advertisers seeking younger consumers.

She recently signed an agreement to serve as the U.S. spokeswoman for Wedgewood, the 240-year-old, high-end pottery company that has launched a new line of casual designs that emphasize "relaxed sophistication."

After her appearance, and a short frenzy of autograph signing, the duchess tucked into a salad, and spoke solemnly in her husky voice of her struggle to be somebody.

Talk of the royal family and her late sister-in-law, Princess Diana, was off-limits. But depending on the circumstance, Fergie teeters between reserve and uncensored honesty about her testy relationship with the ex-in-laws. In February's Harper's Bazaar, the duchess proclaimed that she would not leave the home she lives in with her ex-husband, Prince Andrew, until her divorce settlement is improved, even though the Royal Family already has bought her a $2.5 million mansion.

"All I'm asking is for them to understand that they [her daughters Eugenie and Beatrice] are the Queen's grandchildren. So give me enough to keep them," she was quoted as saying.

And in April's Ladies Home Journal, Fergie bemoaned her treatment in her homeland, saying: "I have been killed and betrayed and sabotaged in this country."

That anger is offset by a personal sea change she is very willing to discuss. While she still battles constantly with "regretting the past," she says she no longer has to prove herself by climbing mountains, petting sharks or participating in other risky behaviors, like getting caught having an affair. And she refuses to be humiliated by people who say disparagingly, "You're doing that fat program."

The duchess says she owes her new confidence to Weight Watchers. It's not just a job, it's therapy.

"Sarah has found herself thanks to Weight Watchers," she says, referring to herself in the third person. Before? "Sarah didn't like herself. That was the reason why she ate."

Weight Watchers advisers have "helped me through the isolation and the loneliness and lack of support about an issue that just happens to be weight."

All in all, things are looking good for the duchess. She is planning to write another children's book about Budgie, the Little Helicopter. "Budgie's coming back, maybe because Sarah's coming back," she says.

And she's ready to push pottery. "It's so nice to eat food on a nice plate," she says as she finishes the salad and rushes back to the airport -- on her way to San Francisco and legions of others hoping to lose their weight and find themselves.