This article originally appeared in Food in Canada and is republished with the permission of the publisher.
It is no secret that our evidence base for food policy in Canada is less than perfect. Historically, we have relied on research tools that are dated, flawed or inconsistent with the current food marketplace. As food policy grows in prominence, do we need to re-evaluate and update our research tools to the 21st century to ensure that sound food law is made?
The Canadian Nutrient File (CNF) is a food composition database maintained by the federal government. The CNF is used for population nutrition surveillance and risk assessment that inform policies and laws, including fortification, salt reduction, food standards and health claims. Despite rolling updates, the CNF is notoriously out-of-date. The evolving food supply and resource limitations have resulted in a CNF that is often inaccurate as soon as it is published.While initiatives to improve the CNF are underway and a new version is expected out this year, there will likely always be some discrepancy between the marketplace and the database that cannot be solved.
Another roadblock to food law enlightenment is self-reported dietary intake surveys. A self-reported dietary intake survey is a cost-friendly tool used by academics and governments to link diet to health outcomes. As part of these surveys, participants are asked to self-report their food and beverage intake over a period of time. Despite methodology to reduce errors, participants tend to underestimate their caloric intake by roughly 10 per cent. This can’t be surprising. I often lie about what I eat to myself, let alone another person. Even if you were honest, could you accurately estimate the portion size and contents of a take-out sandwich? A recent article in the International Journal of Obesity opined that the prevalent use of self-reported data may be leading to conflicting conclusions about the relationship between food components and disease.Further, the authors noted that these conflicting conclusions make it difficult for health professionals to confidently advise their patients and self-reported data should no longer be used for obesity-related policy development.
The limitations of these research tools are well-known and sometimes can be controlled. Nonetheless, should we take a step back to consider the need for greater resource allocation and research innovation at the source? For example, Statistics Canada openly acknowledged that the data used in its 2011 publication on the sugar consumption of Canadians was based on seven-year-old self-reported data using the CNF that was prone to recall bias or selective under-reporting. In addition, the data source did not distinguish between added and naturally occurring sugars. In spite of these limitations, the Statistics Canada sugar report was then used to support the premise that 35 per cent of all sugar in Canadians’ diet came from added sugar in Ontario’s No Time To Wait: The Healthy Kids Strategy. However, Statistics Canada’s added sugar value was extrapolated from the food group and subject to the flaws mentioned above. To bring this full circle, the Healthy Kids Strategy was a key driver in the Ontario government’s school nutrition policy and Bill 45, Making Healthier Choices Act, 2015, which will legislate caloric labelling in restaurants in Ontario.
Overall, conclusions developed using the CNF or self-reported dietary surveys are not without merit. They play a very important role in food policy development and are just examples of weaknesses in our evidence base. Nonetheless, our historical research tools are vulnerable without greater support. The question remains: How do we facilitate policymakers so they can update and modify these tools on a regular basis? Because we all benefit from sound laws based on current evidence.
In the future, I believe all food stakeholders, including industry, NGOs, academia and government have a role to play in ensuring food law is created from a current and accurate foundation by demanding and contributing to frequent updates to food databases and surveys and by prioritizing research tool innovation.