Canadian Total Diet Study

The Canadian Total Diet Study (TDS) is a food surveillance program that monitors the concentrations of chemical contaminants in foods that are typically consumed by Canadians. The TDS measures priority chemicals in food samples either annually, on a pre-determined cycle or in response to a specific food safety issue. Examples of chemicals included in the TDS are trace elements, pesticides, radionuclides, and a variety of other industrial chemicals.

Since its inception in 1969, the TDS has enabled Health Canada to monitor the concentrations of contaminants in foods sold in Canada in order to determine the key dietary sources, assess trends, support the development of food safety policies and regulations, and help ensure the safety of the Canadian food supply.

Health Canada follows guidance provided by the World Health Organization (WHO) for conducting a TDS. TDS surveys are also implemented in other countries worldwide, which facilitates international comparisons and global food safety oversight.

How the TDS is Conducted

Nine Canadian cities that are geographically representative of the entire country are included in the TDS. One of these cities is selected each year for food sampling.

Over a 5-week period each year, approximately 2100 food samples from different food retail outlets or restaurants are collected by the Canadian Food Inspection Agency (CFIA).

Health Canada prepares the foods for consumption as they would be at home, which provides realistic information about contaminant exposure from the diet. Preparation steps include washing, peeling, and cooking. Similar types of foods are combined into approximately 160 composite samples that are frozen at -35°C until analysis.

Health Canada regularly reviews information on the consumption patterns of Canadians and adds new food composite samples to the TDS, as necessary, in order to ensure that the foods most commonly consumed in Canada are included.

How the TDS Results are Used

TDS measured concentrations are then combined with food intake information to provide estimates of the dietary intakes of these chemicals for Canadians. The TDS results on the concentrations of the chemicals in the different food composites are publically available on the Health Canada and Open Data websites. Some TDS results may also be published in peer-reviewed scientific literature.


Health Canada's Bureau of Chemical Safety, Food Directorate leads the Canadian TDS with support from other federal food safety partners, including the Radiation Protection Bureau of Health Canada and the Canadian Food Inspection Agency.

For more information, please contact:

Bureau of Chemical Safety
Health Products and Food Branch
Health Canada
251 Sir Frederick Banting Driveway
Postal Locator 2202C
Ottawa, Ontario
K1A 0K9
Telephone: (613) 957-0973
Fax: (613) 954-4674

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