In 2018, the United Kingdom added a tax to sugary soft drinks to encourage companies to make healthier drinks. A new study shows this tax is working better than expected. By reducing the amount of sugar people buy, the tax could prevent thousands of cases of diabetes, heart disease, and tooth decay over the next decade. The research suggests the tax will save the healthcare system £174 million and help people live longer, healthier lives. This is one of the strongest pieces of evidence yet that taxing sugary drinks actually improves public health.

The Quick Take

  • What they studied: Whether the UK’s tax on sugary soft drinks (introduced in 2018) actually improves people’s health and saves money for the healthcare system
  • Who participated: The entire UK population of children and adults, studied using computer models that predict health outcomes over many years
  • Key finding: The sugar tax reduced sugar purchases by 8 grams per household per week, which is predicted to prevent 12,000 cases of type 2 diabetes, 3,800 cases of heart disease, and 270,000 cases of tooth decay in just the first 10 years
  • What it means for you: If you live in the UK, this tax may help you and your family stay healthier by making sugary drinks less appealing. Even though the changes seem small (less than 1% reduction in obesity), the health benefits add up across the entire population. However, this is a prediction based on a computer model, not proven results yet.

The Research Details

Researchers created a detailed computer model that simulates the entire UK population from 2015 onward. They used real data about how much sugar people buy, how that affects weight gain, and how weight gain leads to diseases like diabetes and heart disease. The model tracks what happens to people over their entire lifetime, calculating how many diseases are prevented and how much money the healthcare system saves.

The researchers started with information from a previous study that measured how much sugar purchases actually dropped after the tax was introduced (8 grams per household per week). They then fed this number into their computer model along with data about UK population health, disease rates, and healthcare costs. The model worked backward and forward in time to estimate the full impact of the tax on the entire population.

This research approach is important because it shows the real-world impact of a policy change. Rather than just measuring whether drinks became less sugary (which was already known), this study estimates how that change affects actual human health and healthcare spending. This type of modeling helps governments decide whether policies are worth the effort and cost.

This study was funded by a reputable government health research organization (National Institute for Health and Care Research). The researchers used well-established methods and real data from multiple reliable sources including government statistics and health surveys. However, the results are predictions based on a computer model, not observations of what actually happened to real people. The researchers were honest about this limitation and noted that they assumed the tax’s effects would stay the same in the future, which may not be true.

What the Results Show

The study predicts that the sugar tax will have modest but meaningful effects on weight. The prevalence of overweight and obesity is expected to drop by about 0.18-0.20 percentage points (meaning roughly 1-2 fewer overweight people per 1,000 people). While this sounds small, when applied to the entire UK population, it adds up to significant health improvements.

In the first 10 years after the tax was introduced, the researchers predict it will prevent 12,000 cases of type 2 diabetes, 3,800 cases of cardiovascular (heart and blood vessel) disease, 350 cases of obesity-related cancers, and 270,000 cases of tooth decay. These are substantial numbers that represent real people who won’t develop these diseases.

Over the lifetime of the current UK population, the tax is predicted to add 200,000 quality-adjusted life-years (a measure that combines how long people live with how healthy they are during those years). In financial terms, the healthcare system is expected to save £174 million in direct medical costs. When you factor in the value of those extra healthy years, the total benefit to society is estimated at £12.2 billion.

The study also found that the benefits would be distributed across the population, affecting both children and adults. The tax appears to work by two mechanisms: first, it makes sugary drinks more expensive, so people buy less of them; second, manufacturers reformulated their drinks to contain less sugar to avoid the tax. Both of these changes contribute to the health benefits. The model suggests that dental health improvements (fewer cavities) would be one of the earliest and most noticeable benefits.

This research builds on previous studies that showed the sugar tax successfully reduced sugar content in drinks and changed what people bought. This new study goes further by estimating the actual health consequences of those changes. Other countries and regions have implemented similar sugar taxes, and this UK study provides strong evidence that these policies work as intended to improve public health, supporting findings from other research on sugar taxes.

The biggest limitation is that this study uses computer predictions, not real observations of what happened to actual people. The researchers had to make assumptions about how reducing sugar intake affects weight gain and disease development. They also assumed that the tax’s effects would remain constant forever, but in reality, people might adapt over time or the tax’s impact might change. The study doesn’t account for other factors that might change in the future, like new medical treatments or changes in people’s behavior. Additionally, the study focuses only on the health benefits and doesn’t fully explore other potential effects of the tax, such as its impact on low-income families or the beverage industry.

The Bottom Line

If you live in the UK, the evidence suggests that choosing drinks with less sugar (which are now more common due to the tax) is a good health decision. Parents should encourage children to drink water, milk, or unsweetened beverages instead of sugary soft drinks. While the tax alone won’t solve obesity or diabetes, it appears to be a helpful tool as part of a broader approach to healthier eating and drinking. Confidence level: Moderate - this is a well-designed study, but the results are predictions rather than proven outcomes.

Everyone in the UK should care about this research, especially parents of children, people at risk for type 2 diabetes or heart disease, and people concerned about dental health. Healthcare professionals and policymakers should pay attention because it shows that the sugar tax is likely delivering on its promise to improve public health. People in other countries considering similar taxes should also find this research relevant. However, people who don’t live in the UK should note that the results are specific to the UK’s tax structure and population.

The study predicts that benefits will start appearing within the first few years, with dental health improvements likely being noticed first. The full health benefits will take decades to appear, as it takes time for reduced sugar intake to prevent diseases like diabetes and heart disease. The £174 million in healthcare savings is predicted to accumulate over the first 10 years, with greater savings appearing over longer time periods.

Want to Apply This Research?

  • Track daily sugar intake from beverages by logging the type and amount of drinks consumed each day. Users can set a goal to reduce sugary drink consumption by 25% over 3 months and monitor progress with a simple counter showing grams of sugar avoided.
  • Use the app to identify your current sugary drink habits, then gradually replace one sugary drink per day with water, unsweetened tea, or milk. The app can send reminders when you typically drink sugary beverages and suggest healthier alternatives.
  • Track weekly sugar intake from drinks over 12 weeks, measuring weight monthly, and noting any changes in energy levels or dental health. Create a long-term goal to maintain reduced sugar beverage consumption and monitor how this contributes to overall health improvements.

This study presents computer model predictions about the potential health benefits of the UK Soft Drinks Industry Levy, not proven results from observing real people. The findings are based on assumptions about how sugar reduction affects health outcomes, and actual results may differ. This research should not be used to replace professional medical advice. If you have concerns about your weight, sugar intake, or risk of diabetes or heart disease, please consult with your healthcare provider. The study was conducted in the UK and may not apply to other countries with different populations or tax structures.