What's the Best Way to Reduce Sugar Intake on a National Scale?

Sugar-sweetened beverages are a major source of sugar intake in children and adults and an important contributor to obesity and obesity-related diseases. Some people have proposed a tax on soft drinks, while others advocate a gradual reduction of sugar—without the use of artificial sweeteners—in soft drinks over a 5-year period as a strategy to reduce overweight and obesity. Two new studies highlight these different approaches.

Researchers led by M. Arantxa Colchero of the Instituto Nacional de Salud Publica in Morelos, Mexico, reported in the British Medical Journal on Mexico’s experience with a tax on sugar-sweetened beverages. In 2013, Mexico’s Congress passed an excise tax equal to approximately a 10% price increase, based on 2013 prices, on nondairy and nonalcoholic beverages with added sugar and an ad valorem tax of 8% on a defined list of nonessential high-energy—dense foods; the tax went into effect on January 1, 2014. The study followed over 6200 households in 53 cities and compared pre- and post-tax purchases of sugar-sweetened beverages.

During the first year of the tax, the average volume of taxed beverages purchased monthly was 6% lower in 2014 than would have been expected without the tax, the study found. The reduction was greatest among the households of the lowest socioeconomic status, averaging a 9% decline during 2014 and up to a 17% decrease by December 2014 compared with pretax trends. Purchases of untaxed beverages were 4% higher, mainly driven by an increase in purchases of bottled plain water. Households of middle socioeconomic status increased their purchases the most.

“The reductions became larger over time, while the purchases of untaxed beverages increased,” the authors noted, a short-term change that is moderate but important. “It will be critical to continue monitoring purchases to see if the trend continues,” they concluded.

Another approach is suggested by Yuan Ma and colleagues at the Wolfson Institute of Preventive Medicine, Barts, and the London School of Medicine and Dentistry, Queen Mary University of London. Writing in The Lancet Diabetes & Endocrinology, they project that a strategy of an incremental and stepwise reduction in free sugars added to sugar-sweetened beverages by 40% over 5 years, without the use of artificial sweeteners, would reduce the prevalence of overweight, obesity, and type 2 diabetes.

Their modeling study used nationally representative data from 2008 through 2012 and British Soft Drinks Association annual reports to calculate sugar-sweetened beverage consumption and its contribution to free sugar and energy intake in the UK population. They calculated the predicted reduction in energy intake, weight reduction, and number of adults with type 2 diabetes resulting from their proposed strategy.

The researchers predicted that a 40% reduction in free sugars added to sugar-sweetened beverages over 5 years would lead to an average reduction in energy intake of 38.4 kcal/d by the end of the fifth year. This would lead to an average reduction in steady-state bodyweight of 1.20 kg in adults, resulting in a reduction in the prevalence in adults of overweight by 1% and obesity by 2.1%.

Thus, they conclude that reformulating sugary drinks as they recommend would result in a reduction of roughly 0.5 million adults from being overweight and 1 million adults from being obese, which in turn would prevent about 274,000-309,000 incident cases of obesity-related type 2 diabetes over the 2 decades after the predicted reduction in bodyweight is achieved. The predicted effect of the reformulation of sugary drinks on adolescents, young adults, and individuals from low-income families was greater.

“The proposed strategy should be implemented immediately, and could be used in combination with other approaches, such as taxation policies, to produce a more powerful effect,” they authors concluded.