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What’s the optimal daily intake of salt and sugar? How much, however, is the quantity we actually consume?

Unless they suffer from specific pathologies, the majority of people do not worry much about what they consume, so that they ritually repeat the gesture of putting one or two sugar packets in the cup of coffee, without thinking about the actual quantity of sugar in them. Just as one has the habit of seasoning dishes even before tasting them. An instinctive gesture, yet harmful¸ in the long term.

These automatic reflexes intervene in order to help us in the decision-making process. It’s not news that we are lazy and rather than getting bogged down in questions and calculations whose answers require a cognitive effort, we tend to leave things as they are, falling victim to two insidious biases: status quo and default option.

Fortunately, to counteract our irrationality Nudges can help: an approach conceived by economist Richard Thaler, 2017 Nobel prize Winner and jurist Cass Sunstein that, starting from the principles of Behavioural Economics, allows to direct people towards choices free from systematic errors to which most individuals are sensitive. This theory finds application in many fields, including health, to promote behaviors that are functional to individual and social well-being.

Going back to the questions posed at the beginning, it is the W.H.O. that dictates the rules and foresees in the 10% of the total intake of calories ingested, the maximum limit of free sugars to be taken daily. In other words: 6 teaspoons per day.  As for salt, the maximum consumption recommended by W.H.O. is 5 grams (2 grams of sodium per day). In both cases, however, we consume, on average, twice as much.

The awareness of “just enough”

In a single dish of fish and chips from a local traditional place in the UK, there is almost half of the recommended daily intake of salt. In order to reduce the amount of salt consumed by customers, experts about nudges have been working on saltshakers. With the goal of correcting the automatic gesture of seasoning, experts have produced new salt shakers, with five holes on the top, instead of seventeen. Thanks to these saltshakers, the amount of salt intake has been reduced by 60%, without sacrificing the customers’ needs.

We don’t fare any better with sugar. That’s because we usually think about sugar in terms of teaspoons, not grams. Nudge Italia substituted standard sugar packets, weighing 7 grams, with smaller 4-gram packets. This brought to a reduction in average sugar intake, from 5.91 to 3.05 grams.

Banning is banned

When designing nudge interventions, it’s important to leave people the free choice. When freedom of choice is lacking, the opposite effect is a risk to foresee, as former New York City Mayor Michael Bloomberg experienced first-hand when in 2012 he proposed to limit the size of sugary drink containers, the so-called Big Gulp (capable of holding 1.9 liters of beverage per glass), to a maximum size of half a liter.

The measure, although approved by the New York City Board of Health, was then rejected by the New York courts: the proposal wanted to prohibit large containers, but in fact it did not prohibit drinking at will, it only forced people to fill their glass several times. The idea was not to be thrown out totally: however, it had to be revisited, in line with the guidelines dictated by behavioral sciences.

If we want to push people towards virtuous and healthy behaviors, we need to give them options from which they have to choose. Bloomberg, though he tried to find a solution to a tricky problem, made a simplemistake: he wanted to ban things. When we have no access to something, the most usual reaction is the reactance, a phenomenon described by psychologist Jack Brehm and present since a young age. In an experiment, 2-year old babies did not express a specific preference for toys they had access to, but they expressed an interest three times higher for those that were behind a plexiglass panel.

When we are subjected to a great pressure that pushes us towards a choice, a behavior or a point of view, we express a violent reaction, taking the name of psychological reactance. It is a resistance that pushes us in the opposite direction, reinforcing the opposite point of view or behavior. Essentially, the reactance is a counterforce that aims at maintaining or reconquering our freedom. We simply fight back.

Rather than banning Big Gulps, Bloomberg could have suggested a change in the design of the container: a shorter and wider glass is more likely to be filled to the brim than one that is taller and narrower. The shape of a glass is the last thing we think about when we drink, yet researchers found that we tend to drink faster from glasses that have curves, compared to glasses that have straight edges. It took seven minutes to the subjects of this study to drink half a pint of beer in a glass with curves, while it took eleven minutes to others, drinking from glasses with straight edges.

Sight matters

Also considering a healthy lifestyle, smaller plates, which contain a smaller portion of food than the usual ones, can be used to eat without feeling hungry afterwards. This was demonstrated by a bizarre experiment in which participants, divided into two groups, were asked to consume a soup.

While one group had a normal bowl, the other had bowls with a hole on the bottom: as they were eating their meal, more soup was being pumped through the hole. The group that was eating from the modified bowls consumed 73% more soup compared to the “controlled” group, without them noticing. Above all, they didn’t feel more satiated. The eyes did the calorie count, not the stomach.

In the face of this evidence, being aware of the power of our irrationality can be a not insignificant competitive advantage.

Laura Mondino