Canada to ban junk food ads targeting kids?

As you may have heard, we have a new Prime Minister here in Canada. This week he gave marching orders to members of his cabinet, and as you might expect, he has some interesting goals for our new Minister of Health, Dr Jane Philpott (full letter available here), which doesn't seem to have received much specific attention as of yet. All of the goals seem reasonable and beneficial to public health, but the ones related to nutrition were of most interest to me, and to this blog (emphasis mine)

Promote public health by: increasing vaccination rates; introducing new restrictions on the commercial marketing of unhealthy food and beverages to children, similar to those now in place in Quebec; bringing in tougher regulations to eliminate trans fats and to reduce salt in processed foods, similar to those in the United States; and improving food labels to give more information on added sugars and artificial dyes in processed foods.

Restricting marketing of unhealthy foods to kids is a great start, but it's a halfway measure. We should restrict the marketing of junkfood to everyone. We should even consider restricting the marketing of all food, period. Here's why.

You might think that seeing a junkfood commercial makes you go out an buy junkfood. They probably do. But junkfood commercials also lead to increased food intake while you are watching TV, or at your next meal (for both kids and adults). For example, the figure below is from a study that showed kids a TV show with or without food ads. Both conditions were provided with a bowl full of goldfish crackers (none of the ads were for the crackers in either condition). While watching the show with food ads, kids ate 45% more food than they did in the condition without food ads. Other similar studies suggest that these effects are likely even greater in children at risk for obesity. Although the effect is smaller in similar studies of adults, it is still substantial (about a 30% increase in food intake).

I question whether this effect is limited to junkfood – if you show me a picture of a delicious apple, I don't see why that's going to have less impact than a picture of a delicious bag of cotton candy. However, the authors of the above study did another experiment where adults were exposed to junkfood ads, commercials with a "nutrition message", and non-food commercials. They found that while junkfood ads increased food consumption, the "nutrition message" commercials resulted in a non-significant decrease in consumption (see figure below).

Restricting all food ads, rather than just junkfood ads, would also avoid the rabbit hole of defining what is or is not unhealthy food (this will be an issue with Dr Philpott's goal of product labeling for "added sugars" as well – will that apply to products sweetened with fruit juice concentrate?).

There are other questions here, such as how to enforce this type of legislation. Although the letter to Minister Philpott says the law should be based on the one in Quebec, my understanding is that the law in Quebec has never been enforced very thoroughly. If anyone knows more about the impact of the law in Quebec, please let me know.

Finally, what should we do with cooking shows, which have also been shown to increase food intake in lab based studies? Should there be a disclaimer at the start of Iron Chef warning people that it may lead to increased food intake compared to Sports Centre?

Junkfood will exist, and it should be allowed to exist. But there is no reason why our society needs unrestricted food ads in popular media.

This story is republished courtesy of PLOS Blogs: blogs.plos.org.