NAFTA’s effect on diet

Has NAFTA, the North American Free Trade Agreement, contributed to Canadian obesity? Barlow et al, in a 2017 paper, suggest it has. Before NAFTA, which was adopted in 1994, Canada had a tariff of 5 percent on high-fructose corn syrup. Under NAFTA, Canada agreed to phase out that tariff, while maintaining tariffs on sugar- and beet-based syrups such as fructose, maltose, glucose and molasses. After the agreement was put in place a years-long decline in total sugar consumption ended, with a shift from liquid sweeteners such as maltose and molasses to corn syrup, a high-fructose sweetener linked to obesity. When high-fructose tariffs dropped, consumption grew: from 21.2 calories of corn syrup per day in 1994 to 62.9 calories per day by 1998. Because tariff reductions make food ingredients cheaper, irrespective of their nutritional qualities, lower prices encourage manufacturers to use more of those ingredients.

The researchers found that consumption stayed flat on those protected sweeteners, but spiked for high-fructose corn syrup. Countries that are economically similar to Canada but not in NAFTA such as Australia and the U.K. did not see a similar effect.

In an interview with the Washington Post, Barlow stated that the connection between free-trade agreements and health has not been well-studied. To date, most research on globalization and nutrition has examined the effects of foreign direct investment: how consumption patterns change when multinational food companies begin producing and advertising in new markets. In trade negotiations NAFTA has often been used as a blueprint. The research leading to the article is an opportunity to think about who benefits from them and who loses, and to construct them to promote health and wellness.

Those interested in this topic are encouraged to read the original research article:

Pepita Barlow, Martin McKee, Sanjay Basu and David Stuckler Impact of the North American Free Trade Agreement on high-fructose corn syrup supply in Canada: a natural experiment using synthetic control methods July 04, 2017 189 (26) E881-E887; DOI: See:

The Washington Post article, includes references to other research studies. Caitlin Dewey, How free trade can make you fat, July 11, 2017: