A sugar tax is a tax on beverages that contain added sugar, designed to raise their price enough to discourage consumption. Over 50 countries and several US cities now levy some form of this tax, typically adding between 10% and 20% to the retail price of sodas, energy drinks, sweetened teas, and similar products. The goal is twofold: reduce sugar intake at a population level and generate revenue that governments can direct toward public health programs.
How Sugar Taxes Are Structured
Not all sugar taxes work the same way. The simplest version is a volume-based tax, where every ounce or liter of a sugary drink is taxed at a flat rate regardless of how much sugar it contains. Malaysia uses this approach. Most sugar taxes worldwide follow this model.
A more targeted design ties the tax rate to the actual sugar content of the drink. South Africa’s Health Promotion Levy, for example, charges manufacturers based on grams of sugar per serving. This structure creates a direct financial incentive for companies to reduce sugar in their recipes, not just for consumers to buy less. A few countries, including Poland and Sri Lanka, use hybrid systems that combine both approaches.
Some taxes use a tiered system with defined thresholds. The UK’s Soft Drinks Industry Levy, introduced in 2018, is the most well-known example. Drinks with less than 5 grams of sugar per 100 milliliters pay nothing. Drinks between 5 and 8 grams per 100 milliliters pay a lower rate, and those at or above 8 grams pay a higher rate. The Center for Science in the Public Interest recommends a similar three-tier design for US jurisdictions, with a cutoff at 7.5 grams of sugar per 12-ounce serving for the tax-free tier.
What Happens to Prices and Purchases
The evidence from cities and countries that have implemented sugar taxes shows consistent drops in sugary drink purchases, though the size of the reduction varies. When Mexico introduced a roughly 10% tax on sugary beverages in 2014, purchases fell by 6.3% in the first year compared to what would have been expected based on prior trends. Low-income households, who tended to drink more sugary beverages, showed the largest reduction at 10.3%. Urban areas saw bigger drops (6.9%) than rural ones (3.9%).
US cities have seen steeper declines. In Philadelphia, sugar purchased through beverages fell by about 31% after the city’s 1.5-cent-per-ounce tax took effect. In Berkeley, California, which became the first US city to pass a sugar tax in 2014, studies found reductions ranging from 10% to 21% depending on the measurement method. One survey-based study found Berkeley residents cut their soda consumption by more than half, though that figure likely reflects some over-reporting.
A 20% tax consistently produces larger effects than a 10% tax. Modeling studies estimate that doubling the tax rate from 10% to 20% roughly doubles the reduction in intake, from about 22 milliliters per person per day to 42 milliliters.
The Reformulation Effect
One of the most striking outcomes of sugar taxes, particularly tiered ones, is that beverage companies change their recipes before consumers ever have to change their habits. The UK levy is the clearest case. In the years between the levy’s announcement in 2016 and its implementation in 2018, manufacturers reformulated aggressively. Of 87 drinks that were initially in the highest tax bracket, 45% dropped their sugar content enough to avoid the levy entirely, and another 15% moved down to the lower tax tier.
The result: the total volume of soft drinks sold in the UK didn’t decrease, but the amount of sugar in those drinks fell by an estimated 30%. This is why many public health experts favor content-based taxes over flat volume taxes. They push the industry to compete on lower sugar levels rather than simply passing a price increase to consumers.
Effects on Weight and Health
The connection between sugar taxes and measurable weight loss is real but modest at the individual level. A 2024 study published in JAMA Network Open examined US cities with sugar taxes and found small average reductions in body mass index. That may sound underwhelming, but small shifts across millions of people add up. Researchers estimated that a reduction of less than 0.2 BMI points sustained over 10 years among California adults could prevent 266,000 cases of obesity and yield 114,000 quality-adjusted life years gained by 2032.
Taxes alone cannot reverse obesity or type 2 diabetes rates. Public health researchers consistently frame them as one tool in a broader strategy that includes food labeling, access to healthy alternatives, and public education campaigns.
Where the Money Goes
Sugar taxes generate substantial revenue, and how that money is spent varies widely. In the US, cities have directed tax revenue toward early childhood education, diabetes prevention programs, and initiatives to improve access to healthy food in underserved neighborhoods. Mexico’s government stated its intention to use revenue to expand clean drinking water access in schools, though the tax wasn’t formally earmarked for that purpose, making it hard to track whether the funds were actually spent that way.
Earmarking revenue for health-related programs can amplify the tax’s impact. Funding free drinking water in schools, for instance, provides a substitute that makes it easier for families to shift away from sugary drinks. Similarly, pairing a tax with media campaigns about sugar consumption or subsidies for healthier beverages creates reinforcing pressure from multiple directions.
Do People Just Switch to Other Unhealthy Drinks?
A common concern is that taxing sugary drinks simply pushes people toward diet sodas, juices, or other calorie-dense alternatives. The data so far suggests this substitution effect is limited. A meta-analysis covering multiple jurisdictions found no statistically significant increase in total untaxed beverage purchases after sugar taxes were implemented. Water consumption showed a non-significant 2.9% increase, and diet or zero-sugar drink purchases rose by a non-significant 4.5%.
Three of the four jurisdictions studied (Berkeley, Mexico, and other US cities) did show some increase in untaxed beverage purchases, but the increases were small relative to the decreases in sugary drink consumption. The net effect on sugar and calorie intake remained clearly negative.
The Fairness Question
Critics often argue that sugar taxes are regressive, meaning they take a bigger bite out of lower-income household budgets. This is technically true. Every study that has examined the question finds that low-income households pay a slightly higher share of their income in sugar tax than wealthier households. But the actual dollar amounts involved are small. Under a typical tax scenario, low-income households in the US would pay roughly $18 to $20 per year in additional tax, compared to $16 to $19 for high-income households. That works out to less than 0.25% of annual household income for the lowest earners and under 0.05% for the highest.
The flip side of this regressivity is that low-income households also show the largest reductions in sugary drink consumption, meaning they stand to gain the most in health benefits. Mexico’s data showed low-income households cutting purchases by 10.3%, nearly double the urban average. If the tax revenue is reinvested in programs serving those same communities, the net effect can be progressive even if the tax itself is technically regressive.