In his book "Lose weight with the forking method" (Maigrir avec la méthode Forking), nutritionist Dr Jean-Michel Borys recommends only letting food past your lips that you can eat with a fork.
The theory is that forking will cut out lots of the most fatty foods that require a knife or a spoon, such as meat with rich sauces and ice cream.
Eating with fingers is also forbidden if you're forking, so cheeseburgers, crisps, pre-dinner snacks and bread are also out.
The other supposed benefit of forking is that the method generally slows down eating, allowing people to feel full up more quickly and reduce the overall amount they consume.
The approach was initially developed by French entrepreneur Ivan Gavriloff, who introduced it to Dr Borys.
"I was sceptical," Dr Borys told Le Parisien newspaper. "But this gentleman was very nice, I listened and he convinced me."
The doctor recommends that forking is practiced in the evenings, which he believes is the time food is mostly likely to be transformed into fat rather than energy. For other meals during the day, all cutlery is allowed.
The author said followers of the diet shouldn't be too hard on themselves.
"If you're invited to a dinner, you should accept," he said. "It's difficult to eat foie gras with a fork so if you're at a party, just go ahead like your friends. Stress makes us fatter."
Dr Borys has tried the approach on 500 patients attempting to lose weight. On average, he claims they lose 1.5 kilograms a month.
Two types of forking are detailed in the book, strict forking and soft forking. The strict method allows only vegetables, cereals such as rice and pasta and fish. Soft forking also permits white meat chopped into cubes, raw beef, shell fish and eggs.