Estimated changes in free sugar consumption one year after the UK soft drinks industry levy came into force: controlled interrupted time series analysis of the National Diet and Nutrition Survey (2011–2019)

Background The UK soft drinks industry levy (SDIL) was announced in March 2016 and implemented in April 2018, encouraging manufacturers to reduce the sugar content of soft drinks. This is the first study to investigate changes in individual-level consumption of free sugars in relation to the SDIL. Methods We used controlled interrupted time series (2011–2019) to explore changes in the consumption of free sugars in the whole diet and from soft drinks alone 11 months after SDIL implementation in a nationally representative sample of adults (>18 years; n=7999) and children (1.5–19 years; n=7656) drawn from the UK National Diet and Nutrition Survey. Estimates were based on differences between observed data and a counterfactual scenario of no SDIL announcement/implementation. Models included protein consumption (control) and accounted for autocorrelation. Results Accounting for trends prior to the SDIL announcement, there were absolute reductions in the daily consumption of free sugars from the whole diet in children and adults of 4.8 g (95% CI 0.6 to 9.1) and 10.9 g (95% CI 7.8 to 13.9), respectively. Comparable reductions in free sugar consumption from drinks alone were 3.0 g (95% CI 0.1 to 5.8) and 5.2 g (95% CI 4.2 to 6.1). The percentage of total dietary energy from free sugars declined over the study period but was not significantly different from the counterfactual. Conclusion The SDIL led to significant reductions in dietary free sugar consumption in children and adults. Energy from free sugar as a percentage of total energy did not change relative to the counterfactual, which could be due to simultaneous reductions in total energy intake associated with reductions in dietary free sugar.

Online supplemental text 3 The term "free sugars" is defined by Scientific Advisory Committee on Nutrition (SACN) to include all monosaccharides and disaccharides added to foods and drinks by manufacturers, cooks, or consumers as well as those naturally present sugars in honey, syrups, unsweetened fruit juice, purees, pastes, and extruded products 5 .Naturally occurring sugars contained within intact plant cell walls (mostly fruits and vegetables, which can be fresh or processed) or in milk (lactose) are excluded from the definition of free sugar.This definition of free sugars is very similar to the published WHO definition of free sugars.
BMJ Publishing Group Limited (BMJ) disclaims all liability and responsibility arising from any reliance Supplemental material placed on this supplemental material which has been supplied by the author(s) Online supplemental text 4 Protein intake was measured and matched to the outcomes of interesti.e.absolute protein intake was the control for absolute free sugar intake and % energy from protein as the control for %energy from free sugars; protein intake from food and drink was the control for free sugar intake from food and drink.
BMJ Publishing Group Limited (BMJ) disclaims all liability and responsibility arising from any reliance Supplemental material placed on this supplemental material which has been supplied by the author(s)  BMJ Publishing Group Limited (BMJ) disclaims all liability and responsibility arising from any reliance Supplemental material placed on this supplemental material which has been supplied by the author(s)

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Quarterly time point number from the start of the study (eg: 1:45) Z Control category (eg: protein consumption = 0, soft drinks = 1) A Pre-announcement = 0, post-announcement = 1 At Quarterly time point number since announcement [0{33}, 1:12] And coefficients are interpreted as follows: β0 : Intercept for protein consumption β1 : Trend change in consumption of protein per day (pre announcement) β2 : Intercept for sugar from soft drinks β3 : Trend change in consumption of sugar from soft drinks across time β4 : Step change in consumption of protein (at announcement) β5 : Trend change in consumption of protein per day (post announcement) β6 : Step change in consumption of sugar from soft drinks (at announcement) β7 : Trend change in consumption of sugar from soft drinks (post announcement) BMJ Publishing Group Limited (BMJ) disclaims all liability and responsibility arising from any reliance Supplemental material placed on this supplemental material which has been supplied by the author(s) : In the study protocol 26 we had planned to examine free sugar consumption changes across different categories of drink (depending on their sugar-content and if they were levy-eligible) and by socio-demographic characteristics at the individual or household-level (including age, gender, equivalised household income and educational qualifications and social class of the head of the household).However, the modest number of individuals represented at each time point (~ 125 adults and 125 children) limited the breakdown of our analysis into sub-groups beyond examination of adults and children separately and food and drinks were not broken down into individual food or drink-types (e.g.: juice only).

Figure S1 :
Figure S1:Observed and modelled energy from free-sugar in food and drinks as a % of energy from food and drinks in adult/children from April 2008 to March 2019.Red points show observed data and solid red lines (with light red shadows) shows modelled data (and 95% confidence intervals) of energy from free-sugar in drinks as a % of total energy intake.The dashed red line indicates the counterfactual line based on preannouncement trends and had the announcement and implementation not happened.Modelled energy from protein consumption in food and drinks (control group) was removed from the graph to include resolution but is available in the supplementary section.The first and second dashed lines indicate the announcement and implementation of SDIL, respectively.

Figure S2 :
Figure S2:Observed and modelled energy from free-sugar in drinks as a % of energy from drinks in adult/children from April 2008 to March 2019.Red points show observed data and solid red lines (with light red shadows) shows modelled data (and 95% confidence intervals) of energy from free-sugar in drinks as a % of total energy intake.The dashed red line indicates the counterfactual line based on preannouncement trends and had the announcement and implementation not happened.Modelled energy from protein consumption in drinks (control group) was removed from the graph to include resolution but is available in the supplementary section.The first and second dashed lines indicate the announcement and implementation of SDIL, respectively.

Figure S3 :
Figure S3: Observed and modelled daily consumption (g) of protein from drink products per adult/children from April 2008 to March 2019.Red points and solid red lines (with 95% CI) show modelled protein consumption from drinks.The dashed red line indicates the counterfactual line based on preannouncement trends in protein consumption and had the announcement and implementation not happened.The light blue lines represents freesugar consumption (g) from drinks as shown in figure 1.The first and second dashed lines indicate the announcement and implementation of SDIL, respectively.

Figure S4 :
Figure S4: Observed and modelled daily consumption (g) of protein from food and drink products per adult/children from April 2008 to March 2019.Red points and solid red lines (with 95% CI) show modelled protein consumption from food and drinks.The dashed red line indicates the counterfactual line based on preannouncement trends in protein consumption and had the announcement and implementation not happened.The light blue lines represent free-sugar consumption (g) from food and drinks as shown in figure 2. The first and second dashed lines indicate the announcement and implementation of SDIL, respectively.

Figure S5 :
Figure S5: Observed and modelled energy from protein as a % of energy from drinks in adult/children from April 2008 to March 2019.Red points show observed data and solid red lines (with light red shadows) shows modelled data (and 95% confidence intervals) of energy from protein in drinks as a % of total energy intake.The dashed red line indicates the counterfactual line based on preannouncement trends and had the announcement and