Fish Tales

Woulda, Coulda, Shoulda Prevented Obesity

The list of ways we woulda, coulda, shoulda prevented obesity keeps growing. In PLOS Medicine this week, another study is spawning headlines about a really effective tool for preventing obesity. The claim is that banning ads for unhealthy food can do the trick. The headlines are promising. For example, PLOS issued  a press release that says:

Television Advertising Limits Can Reduce Childhood Obesity

The Fine Print

However, if you dig into the study, it is a model. Researchers have assembled a set of assumptions about what the effect will be from banning ads for food with high fat, sugar, and salt content might be. If the assumptions are right, then the effect would be to reduce calorie consumption by nine calories per day for children.

Do the math and voilà! The ban saves 40,000 children from obesity.

It makes a nice sound bite. But it’s not really evidence that an advertising ban will actually have this effect. Rather, it’s support for a theory that it might work. A theory worth testing.

What Could Go Wrong?

Marketers are marvelously creative. In fact, creativity is a requisite for working in the field. So it’s not far-fetched to think that food marketers will adapt. Folks who sell junk food will almost certainly devise new tools for selling it.

This is precisely how we have evolved a food supply that promotes obesity. Consumers want food that is pleasing. The industry produces it in forms that are ever more pleasing. Then it finds ways to market more and more of that pleasing food to more and more people all over the world.

An advertising ban on food that can’t dodge being called junk food is just a small speed bump. Food marketers can formulate foods that avoid that label. They can find new ways to market their wares. Commerce has its way. Especially because food is a necessity.

Woulda, Coulda, Shoulda

The history of four decades of efforts to prevent obesity is full of things that woulda, coulda, shoulda prevented obesity. Theoretically, pushing people toward low fat foods should have helped. But it didn’t. Cutting back on sugar should have put a dent in obesity. But two decades of declining sugar consumption has had no obvious effect on obesity prevalence.

In January 2014, Mexico implemented a tax on sugary drinks and junk food. Back then, obesity prevalence was 32.8 percent in Mexico. In 2018, that rate had increased to 36.1 percent. Yet people insist that this tax is effective for preventing obesity because cuts into soda sales.

The UK announced plans for a junk food ad ban like the one described in the PLOS study, but has yet to implement it. We will be eager to see if nine calories per day will indeed save 40,000 children from obesity. Or will this ad ban become just one more failed attempt to bend the obesity curve?

Honestly, though, we need to move beyond suppositions about what ought to work. With more objectivity and curiosity about what really does work, actual progress might be possible.

Click here for the study in PLOS Medicine and here for more from WebMD.

Fish Tales, photograph by Fleeting Pix, licensed under CC BY-SA 3.0

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October 15, 2020

3 Responses to “Woulda, Coulda, Shoulda Prevented Obesity”

  1. October 15, 2020 at 11:38 am, David Brown said:

    “Honestly, though, we need to move beyond suppositions about what ought to work.” Exactly so. But to do that we need to know what does work and why. It all has to do with the impact of polyunsaturated fatty acids on mitochondrial function. Excerpt: “The degree of fatty acid unsaturation of mitochondrial membrane lipids has been found to be one of those biochemical parameters that are most strongly correlated with longevity, when different species of mammals and birds are compared, with a low degree of fatty unsaturation being correlated with less lipid peroxidation and a longer normal life-span.”

    Unfortunately, standard, government-approved dietary advice tells us to swap saturated fats for unsaturated fats to reduce risk for heart attack. It does that all right; mainly by shifting cause of death from heart attack to something else – like COVID-19 complications.

  2. October 22, 2020 at 5:17 pm, Eldad Einav said:

    The critisim is unclear to me. I would not dismiss the study in such strong language. The study meant to help in generating a hypothesis. It’s an idea that needs to be checked further. I would encourage publishing more ideas. This is how science evolves.

    • October 23, 2020 at 4:26 am, Ted said:

      I think we agree. Nothing wrong with publishing hypotheses, so long as they are labeled as such. But the problem here is with the interpretation of a model’s results to say that this strategy “can reduce childhood obesity.” This modeling exercise does not support such a claim. It merely advances a hypothesis – as you say. This matters because such non-evidence is often cited to say that a policy

        is effective

      . So over and over again, we implement policies to prevent obesity based on suppositions and never actually test them.

      That’s a problem.