Sauvage's owner, Boris Leite-Poco, insists that the "Paleo diet" results in greater energy levels, increased muscle mass, clearer skin and even an enhanced sex drive.
"Many think the Paleolithic diet is just some hip trend, but it's a worldwide phenomenon," he told Der Spiegel magazine in an interview published yesterday.
"The trend is probably strongest in the United States where people who have had enough of fast food and generations of illness have taken it up," he added.
Leite-Poco says he has enjoyed a medication-free life since "going Paleo" two years ago.
In Britain, the most well-known convert to caveman cooking is the 71-year-old Welsh pop singer Tom Jones, who claims to have shed two stone after switching to Stone Age food.
"It tells you how to get back to what we used to eat when we were hunters and gatherers - meat, fish and veg," he said.
In the United States, a New York-based group called Evolutionary Fitness has taken the trend a step further. Its members do a lot of climbing and running, as if they lived in fear of marauding wild animals.
However, research started in Britain last year established that Paleolithic man was no raging carnivore. His diet also included a huge variety of plants and berries which was probably supplemented by protein-rich pulses.
Sauvage does not dwell on meat either. Its menu includes salads with olives, capers and pine nuts and smoked salmon with herb dressing.
It chefs cook with unrefined palm oil, coconut oil and home made ghee.
"At Sauvage you know exactly what you eat whereas the majority of restaurants will serve you food which often looks healthy on the outside but can be bulging with invisible unhealthy junk," claims the restaurant's website.
But Eurasia's first Stone Age restaurant has been obliged to make the odd concession to 21st century living.
"We do have a microwave in the kitchen," admits Leite-Poco, "but we try to avoid using it."
- INDEPENDENT