Nudges: A Thousand Tiny Band-Aids for a Thousand Tiny Cuts

Using a small spoon might be a useful tool for preventing weight gain and obesity. That’s the claim you’ll find at the end of a new study in the British Journal of Nutrition. Like many other little nudges, smaller spoons seem to have have an impact on eating behaviors. But like the metaphor of a thousand tiny cuts, obesity has so many causes that we can easily lose count.

So forgive us, but we have to ask. Can a bunch of little nudges add up to a public health strategy with an effect on obesity? Can a thousand tiny Band-Aids fix a thousand tiny cuts?

The Spoon Study

Lewis James and colleagues conducted two sound experiment to test how people ate when using a smaller spoon. Using a randomized, controlled crossover design, the studies compared using a small teaspoon to using a larger dessert spoon.

With the smaller spoon, people took smaller bites, ate slower, and ate less food than with the bigger spoon. The subjects were lean young men. But they didn’t lose any weight. They didn’t need to and that was outside the scope of the study. These effects were measured in single meals, not over time.

So the claim that this might be a good tool for preventing weight gain and obesity is nothing but speculation. Not bad speculation. Just speculation.

The Appeal of Nudges for Obesity Prevention

The idea that a series of simple nudges can serve to prevent obesity is very appealing. Give people smaller plates and they’ll eat less. Put a cute Elmo sticker on an apple and kids will skip the cookies. The list of nudges that have promise goes on and on.

But the nudges don’t always translate into real, long-term outcomes. For example, people with obesity don’t respond to the smaller plate trick. The Elmo sticker study had to be retracted.

We’re not suggesting that nudges can’t be useful. They clearly work for changing specific behaviors. But obesity is not a behavior. It’s a physiological outcome. And we have no evidence for a combination of nudges that will bring better outcomes – either by preventing weight gain or by helping people sustain a lower weight.

As illustrated above, many factors can contribute to obesity. Thus it seems like the problem of obesity springs from a thousand tiny cuts. But it’s not at all clear that a thousand tiny Band-Aids will fix it. We need real evidence for strategies that actually work to reduce obesity.

Sounds good isn’t good enough.

Click here and here for a pro and con viewpoints on the viability of nudging as a strategy for reversing obesity. For a systematic review and meta-analysis of the effects of nudging on dietary behaviors, click here.

Band-Aid Solution, photograph © Paul B/ flickr

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September 8, 2018