The French, it seems, are falling out of love. Not with free health care, or short workweeks, or long vacations in August.
But with bread.
The average Frenchman these days eats only half a baguette a day compared with almost a whole baguette in 1970 and more than three in 1900. Women, still the main shoppers in most families, eat about a third less than men, and young people almost 30 percent less than a decade ago.
The decline is so worrisome that Observatoire du Pain, the bakers' and millers' lobby, started a nationwide campaign in June that champions bread as promoting good health, good conversation and French civilization.
"Coucou, tu as pris le pain?" ("Hi there, have you picked up the bread?") is the campaign's slogan. Modeled on the American advertising campaign "Got Milk?" the bread slogan was plastered on billboards and inscribed on bread bags in 130 cities around the country.
"Eating habits are changing," said Bernard Valluis, a co-president of the lobby. "People are too busy or work too late to go to the bakery. Teenagers are skipping breakfast. Now when you see the word 'coucou,' we want it to be a reflex for consumers to say to themselves, 'Ah, I have to buy bread today.' "
The campaign's Web site, www.tuasprislepain.fr, explains that "France is a 'civilization of bread' and this food is part of the traditional meal 'à la française.' "
Bread is described as healthy and useful in avoiding weight gain. "It is rich in vegetal protein and fiber and low in fat; glucides are a source of energy," the Web site says, using the French word for carbohydrate.
If people on diets want "to avoid giving in to something with fat and sugar, bread is there," it says. "Its satiating effect allows you to wait for the next meal."
Then there is the congeniality effect: "Remember that buying fresh bread on the way home is a simple way of showing loved ones that you have thought about them and of giving them pleasure during the day."
At a bit more than a dollar a loaf, the basic baguette is one of the country's cheapest food staples. Ten billion baguettes are sold every year in France.
A national bread festival is held every May around the feast of Saint Honoré (the patron saint of bakers) so that the French can sample different breads, learn how bread is made and even learn how to become a baker.
And Paris holds an annual contest to select the city's best artisanal baguette maker, with the winner's breads then gracing the tables of President François Hollande at the Élysée Palace for a year. Last month, after an afternoon of tasting 152 baguettes, the jury chose Ridha Khadher, who left Tunisia as a teenager 24 years ago to become a baker in France.
"It's a great honor for a Tunisian to be elected best baguette maker," Mr. Khadher said. "I wonder what the president is going to think about our baguettes."
(Read more: France's Hollande: the euro zone crisis Is over)
Bread is ceding its place on the table to rivals like breakfast cereals, pasta and rice. France may still enjoy the highest density of independent bakeries in the world (32,000), but in 1950 there were 54,000.
According to Steven L. Kaplan, an American historian whom even the French consider the world's foremost authority on French bread, breadmaking has followed two trends in the last century: a steady decline in the quality of most products, and the emergence of a new breed of artisanal bakers devoted to excellence and tradition.
The decline in quality started in 1920 with the transition from slow breadmaking with a sourdough base to a quick process using yeast. Mechanization in the 1960s contributed to the making of bread that lacked taste and aroma.
The trend began to reverse itself in the 1980s. French millers provided bakers with a better flour and more marketing support. The renowned Parisian baker Lionel Poilâne blended large-scale production with artisanal practices like lengthy sourdough fermentation and wood oven baking.
(Read more: France faces 'devastating scandal' as economy stalls)
Then in 1993, the government came to the rescue with a decree that created a special designation: "the bread of French tradition." That bread has to be made exclusively with flour, salt, water and leavening — no additives.
The "tradition," as it is called, is more expensive than the ordinary baguette, which uses additives, a fast-rising process and mechanization, and accounts for about 75 percent of the country's bread sales.
"The methods for making the two breads are not at all the same," said Philippe Levin, a baker in Paris's Ninth Arrondissement on the Right Bank with 25 years in the business. "The secret to making a good tradition is time, time, time. Fermentation is very, very slow. The aromas, the sugar have to emerge. It takes a good three and a half, four hours from start to finish."
To show the difference, he sliced a tradition and then a classic baguette in half and lengthwise as if to make a sandwich.
"Look at all the uneven cavities, the beautiful golden brown crust," he said of the tradition. "Smell the aroma, sweet and spicy. Every one is made by hand. It's magnificent!"
As for the baguette, "It's different, whiter, done by machine."
Mr. Levin sells more traditions than baguettes, even though the baguettes cost 20 cents less. On Sunday mornings his traditions are so sought after that he sets up a special table for customers, who often have to line up down the block.
Both Mr. Levin and Mr. Kaplan, the historian, say the bread lobby's campaign is more cuckoo than coucou.
"My quality has never been better," Mr. Levin said. "My business, too."
Mr. Kaplan was more critical. "This campaign looks like the inside of a white baguette: insipid," he said. "It's asking people to buy bread as part of their routine, like washing your hands or brushing your teeth. We need to talk about bread as an object of pleasure. We need to celebrate breads that make your taste buds dance."