A growing number of countries around the world have implemented taxes on sugar-sweetened beverages in an effort to improve the diets and health of their citizens.

Most recently, the Soft Drinks Industry Levy came into effect in the United Kingdom (UK) earlier this month.

Dubbed the “sugar tax” by the media, it applies to the majority of prepackaged, nonalcoholic beverages that contain at least 5 grams of added sugar per 100 milliliters (less than a third of can of soda) sold in the UK.

It follows a precedent set by similar taxes in other countries, including Mexico, France, Saudi Arabia, and others.

Multiple localities in the United States have also implemented taxes on sugar-sweetened drinks, including jurisdictions in California, Colorado, Illinois, Pennsylvania, Oregon, and Washington, D.C.

While there is currently no national tax on sugar-sweetened beverages in the United States, some public health advocates hope to see one implemented.

“We’re a long way off from a national tax. I think we’re more likely to get more taxes in cities and states, before we ever get a national one,” Barry M. Popkin, PhD, a professor of nutrition at the UNC Gillings School of Global Public Health, told Healthline.

“Will that happen? I bet it will someday,” he continued, “because our health costs are going to skyrocket, and our diet is a big cause of that, and this is kind of the lowest hanging fruit.”

Popkin has evaluated the process and effects of implementing taxes on sugar-sweetened beverages in California, Mexico, Colombia, and other jurisdictions.

He has also learned that it takes time and effort to build public support for these taxes.

“The reality is that it took us 6 or 10 years to get a national tobacco tax [in the United States],” Popkin said.

“We never have taxed something like tobacco or food first at the national level. It’s taken a lot of shifts in the population’s opinion before that happens,” he added.

Soda taxes might shape consumer habits

Regular consumption of sugar-sweetened beverages has been linked to higher risk of type 2 diabetes, heart disease, metabolic syndrome, and several other conditions.

Drinking sugary beverages on a regular basis can also cause people to consume more calories than they otherwise would.

“When we drink sodas and other sugary drinks, we may feel full, but we do not subsequently reduce the amount of food we eat, so total calorie intake increases,” Popkin told Healthline.

Early studies suggest that soda taxes might help reduce the consumption of sugar-sweetened beverages.

For example, Popkin and colleagues have found that purchases of sugar-sweetened beverages fell by 8.2 percent on average in the two years following the implementation of a tax in Mexico.

Likewise, a new study reported in the American Journal of Preventive Medicine suggests that a beverage tax on sugar-sweetened drinks in Philadelphia might be affecting consumer behavior.

The investigators found that Philadelphians were 40 percent less likely than people in comparison cities to report drinking sugar-sweetened soda on a daily basis after the tax was implemented.

They also found that survey respondents in Philadelphia were 58 percent more likely to report drinking bottled water on a daily basis after the tax came into effect.

Taxes on sugar-sweetened beverages might also push manufacturers to reformulate their products and adjust their marketing strategies to sell more sugar-free offerings.

For example, the UK government claims that over 50 percent of beverage manufacturers have reduced the sugar content of products in anticipation of the new levy.

In cases when people forgo soda in favor of water, reduced consumption of sugar-sweetened beverages might lead to reduced rates of type 2 diabetes and other diet-linked conditions.

However, it’s possible that some people might replace soft drinks with fruit juice or other products that contain high levels of natural sugars that aren’t taxed.

Furthermore, taxes on sugar-sweetened beverages don’t target other sources of sugar in people’s diets or lower the cost of nutrient-rich foods and drinks that many people struggle to afford.

Tax advocates face resistance from multiple sides

Soft drink manufacturers have spent millions of dollars on court cases and public information campaigns to challenge taxes on sugar-sweetened beverages.

In the United States, Republican lawmakers have also introduced legislation to kill soda taxes.

In addition to these pro-industry and conservative voices, soda tax advocates also face resistance from some people on the left.

Some critics have argued that soda taxes are regressive, which means they take a higher percentage of income from low-income people than high-income people.

In response, Popkin suggested that taxes on sugar-sweetened beverages promote behavioral changes that will disproportionately benefit low-income communities.

“In most countries, lower-income households consume more sugary drinks, so they suffer more from obesity, diabetes, and other diet-related illnesses,” he told Healthline.

“The costs of these diseases — treatment costs, loss in productivity, loss of quality of life, family members providing care — are also a heavier burden on lower-income households compared to higher-income households,” he added.

However, not all critics find these arguments compelling.

For instance, Melina Packer, PhD candidate in the Department of Environmental Science, Policy, and Management at University of California, Berkeley, describes these taxes as “myopic” and “stigmatizing” in how they target individual consumers, particularly in low-income and minority communities.

“The health disparities that low-income people face are far more complicated than soda, or even sugar, alone, and stigmatizing this single product (along with those who consume it) will do little to reduce, and may even exacerbate, the health issues produced by poverty and discrimination,” Packer told Healthline.

Rather than punishing consumers for drinking soda, she would like public health advocates to target corporate and government practices that contribute to economic inequality.

“Countless epidemiological studies have linked chronic stress, disturbed circadian rhythms, dangerous and precarious work, and exposure to environmental toxins with adverse health outcomes, all of which disproportionately burden poor folks and people of color,” she said.

“If public health advocates want to help low-income people and mitigate the transgenerational effects of institutional racism,” she continued, “they should re-direct their resources toward stronger chemical regulations, better workplace and union protections, socially just immigration policies, and single-payer healthcare.”