Canada's federal government is putting the country's food producers on a strict carbohydrate labeling diet that could knock a number of new product lines off grocery store shelves next year.

Health Canada says there is no scientific evidence to support low-carb diets, such as the ubiquitous Atkins diet, and the absence is reflected in new rules on labeling that come into effect in December 2005.

"There was -- and still is -- no reason from a nutrient point of view to be concerned with the amount of carbs that we eat," said Carole Saindon, who was speaking for Health Canada.

So, when Health Canada published its new regulations last year, carbohydrate claims were ruled off-limits for future food and drink labels.

"Low fat is one of them, low sodium is one of them, but low carb is not," said Saindon.

The restrictions, which come into effect next year for large companies and in 2007 for producers with revenues of less than $1 million, do not stop there.

An information letter from Health Canada has informed the industry that "express or implied representations" are prohibited.

"This means that other statements about the presence or absence of carbohydrates, including the use of brand names and trademarks, are subject to these regulations," says the letter.

The rule change comes as thousands of new low-carb products are being introduced in the U.S., many of them spilling over into Canada.

In April, Unilever Canada launched a 22-product Carb Options line following a January launch in the United States.

The hardline government stand on carbohydrate claims for new Canadian food labels has prompted a sharp retort from the purveyors of the Atkins low-carb diet.

When the rules take effect next year, carbohydrate content must be listed on the Nutrifacts table on all food and beverage packaging. However, other carb-related claims, including in the product's brand name or trademark, will be prohibited.

"I take exception to saying there's no science to this approach and that it's unhealthy," Colette Heimowitz, an Atkins vice-president, said from New York.

"It takes big government agencies a while to embrace the research. But at least acknowledge the research that has been done in the last three years."

The company issued a news release contending 37 different studies have shown that "controlling carbohydrate intake is key to healthy nutrition, achieving and maintaining a healthy weight and to good overall health."

Health Canada says it is simply following the guidance of the U.S.-based Institute of Medicine, which in 2002 recommended 45% to 65% of a person's daily caloric intake be from carbohydrates.

"There are no recommendations to decrease carbohydrate intake. All recommendations are that carbohydrate is the major source of calories in the diet," said Christina Zehaluk of Health Canada's bureau of nutritional sciences.

"Therefore, based on that science -- based on those dietary recommendations -- it was considered inappropriate to have claims which highlighted foods that were low in carbohydrates.

"For the general public, there's no need to reduce carbohydrate intake or to look for foods that are lower in carbohydrate."

Because they imply carbohydrate benefits, said one official, trademarks such as Unilever's Carb Options line likely will be prohibited when the regulations take effect December 12, 2005.

One group potentially affected by the changes are diabetics. Peter Hope-Tindall of Toronto says the low-carb diet craze has made his life easier in grocery store aisles.