PARIS, FRANCE (By Julia Reed, NYTimes) February 6, 2007 — When I was 15, I studied in France, at the University of Strasbourg, for six weeks. On weekdays, my fellow American students and I ate lunch in the school cafeteria and discovered the wonders of braised rabbit and coq au vin, followed always by an apricot tart or napoleon (my first ever!) at the nearby patisserie. On weekends we toured the country by train, fortified by bread and (real!) cheese, along with copious amounts of cheap red wine. Already weight-obsessed, I was sure I'd put on at least 10 pounds. But when I stepped off the plane, the jaws of my waiting parents and my best friend literally dropped. It turns out I'd lost 10 pounds — I'm not sure I've looked as good since.

Mireille Guiliano had quite a different teenage experience abroad. As an 18-year-old from a small town in eastern France, she spent a year as an exchange student in the well-to-do Boston suburb of Weston, Mass., where she discovered the distinctly American joys of bagels, brownies and chocolate chip cookies and gained 20 pounds. When her own parents met her ocean liner in Le Havre, they were as stunned as mine were, but for a different reason — her father told her she looked like a sack of potatoes. ''I could not have imagined anything more hurtful,'' she writes. ''And to this day the sting has not been topped.''

Never fear — Guiliano's story has a happy ending. After a few miserable months during which she gains more weight, cries herself to sleep and hurries past mirrors clothed in shapeless flannel shifts, her mother brings in the family doctor, a k a ''Dr. Miracle.'' He detoxes her with leek broth for a weekend, teaches her to become a master of both her ''willpower'' and her ''pleasures,'' and supplies her with recipes, including one for apple tart without the dough. She learns to love walking, finds her ''equilibrium'' and goes on to become C.E.O. of Clicquot Inc. and a director of Champagne Veuve Clicquot.

Most remarkably, despite the fact that she dines out 300 times a year and enjoys two- and three-course meals for lunch and dinner every day — always accompanied by a glass of Champagne — she has remained thin.

Guiliano recommends Dr. Miracle's plan as the French way, but it is not unlike the advice that American nutritionists on Web sites and at spas and clinics across the country dispense every day. It is exactly the advice I got last year at Dallas's Cooper Clinic during my annual physical: if you want a glass of wine with dinner, don't eat the bread or skip the baked potato. Do some aerobic exercise; if you're over 40, lift weights. Keep a food diary and cut out the processed junk. Slowly changing your eating habits is far more effective than any crash diet. You don't have to deprive yourself if you learn to make trade-offs. And on and on.

Somehow, though, these sensible stratagems are more palatable coming from Guiliano, who was once fat herself, and who now happily lives in America, where she first fell victim to our bad habits. She knows we eat too fast in front of the TV or with newspaper in hand, while French women make a ritual out of every meal. She knows we eat portions that are too big and food that is too bland. French women, on the other hand, stress flavor and variety over quantity and, therefore, are more satisfied with less. (Bland food and too much of one kind, a big bowl of pasta for example, breeds boredom, which leads you to alleviate it by eating more.) She knows our tendency to gorge ourselves on Snickers bars rather than savoring a single piece of fine dark chocolate. French women eat slowly and ''with all five senses.''

Indeed, much is made of the superiority of French women in all things, from chewing to ''using the same scarf to create a different effect'' to ''preserving spark and mystery'' in long-term relationships. Apparently, they're even better at being happy — ''the French woman understands intuitively that one does not laugh because one is happy; one is happy because one laughs.'' This gets a tad tiresome, but I forgive Guiliano her patriotic fervor and her endless aphorisms because she is on to something. After all, I lost 10 pounds by walking off my daily pastry and eating small portions of once exotic dishes (at the university cafeteria they never filled your plate). Also, who can blame her for branding? If a lot of what she dispenses is universally sound advice with a French label, she's smart to apply it. We may profess to despise her compatriots in all their arrogance, but secretly we still find Paris far sexier than South Beach.

I think our problem with the French has always been jealousy. We have an inferiority complex, at least stylewise. French women can do more with a scarf. We wish we had their innate chic, their effortless discipline, their easy appreciation of all things sensual — their impossible thinness. When I begged my parents to send me abroad, it was not to, say, Germany that I wished to go. Desperate to be sophisticated, it was French that I wanted to learn, France that I wanted to know. (Now of course, I wish I'd studied the far more useful Spanish.) Despite all our achievements in what used to be the exclusively French provinces of fashion, food and wine, the real milestones for many of us remain our first Chanel suit, our first sip of Petrus or Chateau d'Yquem, our first time at La Grenouille or La Tour d'Argent. And then there is the fact that while close to two-thirds of American adults are either obese or overweight, French women really don't get fat.

The reason behind that most enviable difference, says Guiliano, is that ''French women take pleasure in staying thin by eating well, while American women see it as a conflict and obsess over it.'' Put another way, ''French women typically think about good things to eat. American women typically worry about bad things to eat.'' She says she is constantly appalled that American cocktail parties are filled with chatter about diets, a subject that shouldn't be deemed proper conversation. She says eating in America has become ''controversial behavior'' and that our obsession with weight is growing into nothing less than a ''psychosis'' that she believes adds stress ''to our already stressful way of life,'' which is ''fast erasing the simple values of pleasure.''

She urges us to relax. Walk to the market, breathe in the fresh herbs, cook a good dinner, have a glass of wine or champagne (preferably Veuve Clicquot). Just sip it slowly (she makes hers last through a meal). She rejects the ''American rule'' of ''no pain, no gain'' and describes exercise machines as a ''vestige of Puritanism: instruments of public self-flagellation to make up for private sins of couch riding and overeating.'' By all means go to the gym if you really love it, she says. Otherwise take the stairs and pick up some weights in the privacy of your own home. She finds walking an indulgence that allows time for ''freedom of thought,'' and says French women walk an average of three times as much as American women do. She proudly reports that during the 2003 blackout she easily made it past the younger people in her building who were huffing and puffing on the stairs.

Sometimes these ''simple values'' seem perhaps too simple. Many of us need the discipline of the gym and don't have time to stroll to the open-air market (which probably doesn't exist where we live) or set a proper table twice a day. My own early lessons in the civilized life sadly didn't take. The summer I returned from France, a McDonald's opened in our town and a Big Mac suddenly seemed as exotic as a nicoise salad. I failed miserably at what Guiliano calls ''recasting,'' emphasizing quality over quantity in both meals and exercise.

But, armed with her book, I am willing to try again. There is no scientific ''food plan,'' just suggestions and seemingly indulgent recipes, including one for fingerling potatoes and caviar. Guiliano reminds us that a half-dozen oysters contain only 60 or 70 calories, that soups fill you up and supply much-needed water to your body (''The theory goes that the French, who eat soup up to five times a week for dinner, eat better and less.'') Her mother's ''soupe aux légumes'' is worth the price of the book alone, but I am less sure about her own ''Chicken au Champagne,'' which requires you to pour a cup of champagne over some chicken breasts and then broil them. After tasting one, I can say with certainty that I'd rather have the Champagne in the glass and that I would definitely not serve the chicken to company along with, as she suggests, brown rice and mushrooms. I'm also not entirely sure about Dr. Miracle's apple ''tart'' with its cabbage leaf ''pastry'' (not for eating, necessarily, but ''for presentation''). Still, sans cabbage leaf, it's a good idea, and her snapper with almonds is good full stop, as is the delicious tagliatelle with lemon.

Guiliano ends the book with a list of more observations about French women. They don't weigh themselves, they don't snack all the time, they eat more fruit but would never give up their bread or other carbs. They dress to take out the garbage, they understand the importance of a good haircut and expensive perfume, they know love is slimming. Part of me wanted to throw the book across the room, while the other part was memorizing the list. I actually found myself resolving to learn to eat with all five senses — or at least to try to turn off ''All My Children'' during lunch breaks. I did not even throw up when I got to the line that encouraged me to savor ''all the little things that make each day a miracle,'' so that I may not need a shot of Scotch (French women don't drink hard liquor) or a quart of Haagen-Dazs to get me over the top. At the very least, we would all do ourselves a favor to make like Colette, for whom the table was ''a date with love and friendship '' instead of the root of all evil.

Julia Reed is senior writer for Vogue and author of ''Queen of the Turtle Derby and Other Southern Phenomena.''