It's enough to make any self-respecting French gourmet spit out his lunch with disgust.
The "jambon beurre" (ham and butter), a staple of the French diet for centuries, is fast losing ground in the fast-food market to the burger, according to the report by food marketing group Gira Conseil.
The ham sandwich is still selling like hot cakes -- with 1.28 billion wolfed down last year.
But the burger is catching up, with 1.07 billion eaten last year, a rise of 10 percent compared to the previous year.
And if the current trend continues, it will soon be the most popular sandwich in France, as consumption of the "jambon beurre" was up only three percent this year.
The burger is now "one meal in four" in France's fast-food restaurant landscape, said Gira Conseil.
"Burger-mania is far from being over in France," added Gira Conseil boss Bernard Boutboul.
US fast-food chain McDonald's has tasted significant commercial success in France and rival Burger King has begun to open a few restaurants in Paris.
Judging by the long queues outside one of the Burger King restaurants at the busy Saint Lazare station in Paris, the French appetite for burgers remains unsatisfied.
With inflation low in France at the moment, the price of the ham sandwich was relatively stable last year, rising by a mere 1.05 percent to an average of €2.74 ($3.02).
Unsurprisingly, the famously pricey French capital is the most expensive place to munch a ham sandwich, with the average baguette weighing in at €3.18.
The ports of Sete in the south of France and Dieppe in the north are the cheapest, at an average of €2.36.
The French are also avid gobblers of pizza, with 809 million consumed last year (up 1.20 percent), the survey revealed.
"France is one of the two biggest pizza countries in the world," said Boutboul -- just behind the United States and way ahead of Italy.