Humanity has a love-hate relationship with sugar: It’s a treat reserved for the end of a good meal, a focal point for holidays, even a term of endearment. But sugar is an enemy, too, long disparaged as empty calories that cause tooth decay and weight gain. In recent decades, sugar’s bad image has grown much worse. For many, it’s displaced fat and starch at the top of the list of dietary bogeymen. Public health experts have stepped in with advice that we distinguish between the naturally occurring sugars — what’s found in milk and oranges, for example — and “added” sugars that sweeten soft drinks and other packaged foods. Increasingly, governments are treating sugary sodas like cigarettes and alcohol and taxing them to discourage consumption.


The Situation
With obesity and its attendant health problems — diabetes, heart disease and cancer — on the rise, and added sugar fingered as a major culprit, advocacy groups are working to persuade people to cut back. (Among them are Bloomberg Philanthropies, the charity of Michael Bloomberg, founder and majority owner of Bloomberg News parent Bloomberg LP.) In the US, where four in 10 adults are obese, the average person gets more than 13% of total calories from added sugar. The World Health Organisation recommends a maximum of 10%, or about 12 teaspoons a day: the amount in 15 ounces of Coca-Cola. To make the advice stick, more than 30 countries and a handful of US cities have begun to tax sugary beverages, which studies suggest are the biggest problem. Another strategy is to strengthen labelling requirements for packaged foods. Chile, where people take in more calories from sugary drinks than anywhere else in the world, now requires conspicuous front-of-package stop-signs on foods high in sugar (or sodium, saturated fats or calories) and forbids advertising such products to children. In the US, products must carry a notice of their added sugar content by 2020.


The Background
Molecule for molecule, added sugars are no less wholesome than natural ones. Whether it’s honey, molasses, refined cane sugar or the sweet stuff in an apple, it’s glucose, fructose or a combination of the two. But natural sugars come in limited amounts as part of a package that contains nutrients and fibre, which slows sugar digestion, giving the liver more time to metabolise it and preventing unhealthful spikes in blood sugar. By contrast, added sugars typically come in abundance, and, in the case of soda, unaccompanied by nutrients. That extra sugar prompts bacteria in the mouth to produce acids that erode tooth enamel. Drinking sugary beverages exacerbates anyone’s tendency to become obese, because people can drink a lot of soda without feeling full. Suspicions that sugar may be habit-forming are supported by evidence that laboratory rats demonstrate the classic addiction symptoms of craving, bingeing and withdrawal. Low-calorie foods and drinks containing artificial sweeteners obviously cut back on calories, but some evidence indicates that they may increase appetite and, because they are so sweet, keep people craving the taste of sugar.


The Argument
The way to prevent added sugar from causing problems, soda companies have argued, is to see that people get plenty of exercise. Physical activity indeed helps keep weight off, but limiting the calories going in, studies show, make a bigger difference. Critics of soda taxes argue that they are a burden on the poor and threaten job loss in the food industry. Mexico’s experience, however, suggests that wealthier people end up paying the taxes, while poorer people cut out sugary drinks. The evidence so far in Mexico and Philadelphia also finds no employment backlash from soda taxes. Overall, the taxes appear to be working. For example, a peso-a-litre soda tax in Mexico imposed four years ago ushered in a 7.6% drop in consumption. (This research was funded by Bloomberg Philanthropies.) Philadelphians dialled back their urge for a daily soda by 40% almost immediately after a 2017 city tax went into effect. In the UK, a soda tax levied not simply by the litre but according to the amount of sugar per litre has pushed beverage makers to reduce the sugar content in their products.