PARIS -- Is France, the land of confectionary delights, ready to go on a diet?

The French Court of Appeals has just made it easier, overturning a 1902 law that classified artificial sweeteners as medicines to be sold only in pharmacies and that prohibited their use in any food products. Diet Coke, Pepsi Light, diet cookies, diet jams and other staples of American weight-watchers had been conspicuously absent from supermarket shelves here.

It was not a matter of the French passion for purity of ingredients in cooking. It all harked back to the fears of the sugar lobby at the turn of the century when the new artificial sweetener saccharin came on the scene. Buried in a parliamentary budget bill, the anti-saccharin law had held back the "lite" revolution in France to this day.

The latest court decision came as the result of a restraint-of-trade lawsuit by one of the largest French supermarket chains, Centre Distributeur E. Leclerc, which wanted to sell diet products and sweetener tablets in its stores. The court found that since other member European Community countries do not restrict the sale of products with sugar substitutes, France had effectively created an illegal monopoly situation for its pharmacies.

Moreover, a recent report commissioned by the French Health Minister had found that there was nothing medicinal about aspartame, saccharin and other artificial sweeteners. The court said the sweeteners could no longer be packaged as medicine.

Michel-Edouard Leclerc, co-president with his father of the supermarket chain, was jubilant about the court decision. "The victory we've obtained is the end of a monopoly by the pharmacies of a product," he said, "but just as important, it will open the French market to new eating habits."

Leclerc said the artificial sweetener tablets are now available in his stores and that in another two or three months a diet Coca-Cola will be on his shelves. French bottlers are not set up yet to make the low-calorie Coke formula, he said, explaining the delay. He judged that the market in France for Diet Coke and Pepsi will be "enormous."

The change in French eating habits was evident in the supermarkets and restaurants here before the sugar-free court decision. Where once the high fat content of his cheese was something for a merchant to boast about, now low-fat milk products are suddenly appearing in stores. Hediard, a famous gourmet store, has a new line of jams with half the ordinary sugar content. New commercials for food products that can be touted as healthful and light are filling the television screens. Nouvelle cuisine, spare and light, began here.

It remains to be seen whether the sugar-free revolution will spell the end of pain au chocolat and other French delights or simply spawn a sugarless pain au chocolat. Somehow, it wouldn't be the same.