On vacation in France, a food writer grows slimmer while her meringue obsession grows.

Since there are absurdly few occupational hazards to my job as a food writer, I grumble about the one odious problem: too much great food. Whether I'm testing recipes or going to restaurant openings, I am always consuming more calories than my body can burn. I keep my intake under control at home, but when I travel, I go wild. I come home feeling fat and uncomfortable, and then diet on lettuce leaves and carrots until I'm back to normal.

On a trip to Paris one Christmas, I complained about this dilemma to my friend and hostess, the petite Caroline Ducrocq, a screenwriter and the wife of one of my oldest friends, the actor Howard Hesseman. I begged her to tell me how she keeps her figure, which is minute enough to provide steady employment to the seamstresses at Azzedine Alaia and Jean Paul Gaultier. (Their smallest size is too big for her.) Believe it or not, she has a very healthy relationship with food and loves to eat.

She told me that if I ate as she did, I would lose weight during my time in Paris. Here were her rules: no snacking between meals, no eating unless I was hungry, walking as much as possible, drinking lots of water and eating only fruits, vegetables, proteins and butter or olive oil. "Carbohydrates do not pass my lips," she told me in her fetching Parisian accent.

The carbohydrates she referred to were pasta, bread, potatoes and rice. Sugar was out too. But that left a variety of extraordinary Parisian foods to enjoy, and I was happy. For a while.

Lunch was sometimes fish in a butter sauce with perfectly cooked little bundles of haricots verts, a glass of red wine or champagne, and, of course, coffee. We ate crisp salads, sometimes just mixed greens in a big white bowl or Belgian endive with walnuts, pears and goat cheese. Maybe we had a selection of celery root, beet and carrot salads or a salad of frisée with lardons and a poached egg on top. If we knew we'd be having a late dinner, we distracted ourselves from late-afternoon hunger by going to museums, galleries, movies, plays or shops.

We chose a different restaurant each time we went out for dinner with friends. We watched people come and go instead of watching the contents of the breadbasket diminish. We had all kinds of fish, stews, meat. Other times we ordered huge platters of oysters and exotic fruits de mer. Three or four of us would sometimes share a particularly irresistible dessert--a prune soufflé, a pear tart with Calvados custard. We almost always had a digestive tea, such as chamomile or verbena, to settle our stomachs and extend our time at the table. Often we'd take an hour or more to walk home.

This weight-loss regimen was going beautifully, but something in me started to rebel. "No sugar, no carbohydrates" began to eat away at me. I needed something indulgent.

One afternoon I saw the solution in the window of a charming old patisserie: white meringues, coffee-colored meringues, meringues drizzled with a thread of dark chocolate, pearly slivered almond meringues, even pale pink strawberry meringues. I bought one. I found sublime pleasure in its lightness, sweetness and crunch.

I began to obsess about meringues. At times I was so overcome I would find myself in a trance in front of a patisserie. I sought them out in different arrondissements. I had to have one every afternoon. I rationalized that they couldn't be too harmful since they are made mainly of egg whites and air with just a little sugar--a perfect diet food, really. Plus they took the edge off my hunger and gave me a spurt of energy.

I grew fascinated with the contradiction of their chewiness and crumbliness. I even learned a little about their history. Some scholars believe meringues were invented in the Swiss town of Mehrinyghen in 1720. The first meringues in France were served to the exiled King Stanislas I of Poland, who in turn served them to his daughter, Marie Leszczynski. She passed her passion on to her daughter-in-law, Marie Antoinette.

Did I mention that I had not spoken of this meringue business to the scrupulous Caroline? It had become important not to disappoint her. Besides, my meringue habit didn't seem to be interfering with my Parisian weight-loss program, to judge by the way my clothes were hanging.

I was feeling good. But then one afternoon I felt deprived--not only because I couldn't fit into a particular dress that I loved at Gaultier but also because its price was absolutely out of my range. I felt like a large, poor American. I ducked out of the store. And that's when I happened to find Au Panetier, the most charming Belle Epoque patisserie imaginable, with recherché details capable of whipping a sugar fiend into an absolute fit. I bought two meringues and ate them as I walked back to Gaultier, where I found Caroline fitting into everything she tried on and Howard delighted to buy it all for her.

"What are all those little crumbs on your sweater?" Caroline asked.

Busted. I admitted my deviation. Crestfallen, she told me I was on my own. "Fine," I challenged her. "You'll see. It won't make the slightest bit of difference in my diet program."

I carried on with my meringues, and by the time we went south for New Year's, my jeans were looser and my cheekbones more prominent. A week or so later, when I returned home to San Francisco, I weighed myself and found that I'd actually lost five pounds. And I had done so by eating the very best food I could find, the best of toutes les choses françaises--and at least two dozen meringues.

Peggy Knickerbocker is the author of Olive Oil: From Tree to Table (Chronicle Books).