Montignac, who died last weekend, developed a crash diet based on never eating "bad" carbohydrates at the same time as fats after suffering from obesity himself as a child and battling persistent weight gain.

After testing the principle of disassociating the two on himself, losing 30 pounds (13.6 kilogrammes) in less than three months, he wrote "Dine Out and Lose Weight" in 1986, a book that shot to the top of the best-seller list in France where it sold half a million copies.

The following year he released his most well-known book "Eat Yourself Slim and Stay Slim", which sold millions of copies in 40 countries, according to his website.

His weight-loss recipe classifies carbohydrate-rich foods according to a glycemic index (GI), based on their effect on blood glucose levels after meals.

"Bad" high-GI carbs may not be taken together with fats as Montignac believed these combinations would lead to fats in the food being stored as body fat.

France's latest diet guru is Pierre Dukan, whose slimming plan that kicks off with a "protein only" attack phase is selling by the armload in bookshops.