The study investigates the effects of the UK's Soft Drinks Industry Levy (SDIL) on individual-level free sugar consumption. The SDIL, introduced in April 2018, aimed to reduce sugar content in soft drinks by encouraging manufacturers to reformulate their products. The study utilised data from the National Diet and Nutrition Survey (2011-2019) and employed a controlled interrupted time series analysis to compare observed sugar consumption against a counterfactual scenario without the SDIL. Data was gathered from 7999 adults and 7656 children between the age of 1.5 -19 years old using 3 – or 4 – day food diaries.
Results
The results showed significant reductions in daily free sugar consumption from the overall diet:
- Children reduced their free sugar intake by 4.8 grams, and adults by 10.9 grams.
- Free sugar intake from soft drinks alone decreased by 3.0 grams for children and 5.2 grams for adults.
- While the absolute intake of free sugars declined, the percentage of total dietary energy from free sugars did not significantly change relative to the counterfactual scenario, indicating that the reduction in free sugars was accompanied by a simultaneous reduction in overall energy intake.
The study concludes that the SDIL led to significant reductions in free sugar consumption from soft drinks and across the whole diet, reinforcing the effectiveness of sugar reduction strategies and supporting the extension of such policies. Despite the reductions, free sugar levels remain above the World Health Organization's 5% recommendation for total energy intake.
The study's strengths include the use of nationally representative data and consistent dietary assessment methods over an extended period, allowing for a robust analysis of trends and impacts. Limitations include potential under-reporting of dietary intake and the inability to account for all possible confounding factors.
