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Trial registered on ANZCTR


Registration number
ACTRN12620000858998
Ethics application status
Approved
Date submitted
5/06/2020
Date registered
28/08/2020
Date last updated
5/10/2022
Date data sharing statement initially provided
28/08/2020
Date results provided
15/10/2021
Type of registration
Prospectively registered

Titles & IDs
Public title
Exploring the effectiveness of policy options for added sugar labelling in Australian adults
Scientific title
Exploring the effectiveness of policy options for added sugar labelling on purchasing behaviour in Australian adults
Secondary ID [1] 300891 0
NIL
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Promotion of healthy diet choices 317601 0
Obesity 318822 0
Condition category
Condition code
Public Health 315680 315680 0 0
Other public health
Public Health 316158 316158 0 0
Health promotion/education
Diet and Nutrition 316441 316441 0 0
Obesity

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
We will examine the relative effectiveness of different added sugar labelling options for three food product groups (breakfast cereals, yoghurts and non-alcoholic packaged beverages) using one sequential randomised controlled trial.

Trial:
A third-party recruitment company will be used to recruit participants for the online study. The recruitment company have security measures in place to securely store participants’ identifiable data. No identifiable information will be received by the researchers from the recruitment company. Research data (i.e. answers to the survey) will not be available to or stored by the recruitment company.
Eligible participants will be randomised to complete one of seven online survey conditions that will take approximately 10-15 minutes to complete.
Participants will be screened in order to classify them as high or low sugar purchasers. Participants will be asked to select all relevant products they purchase at least once a month for themselves or their household from a range of generic product subcategories in each of the product categories of interest (yoghurt and custards, breakfast cereal and non-alcoholic packaged drinks). For example, in the yoghurt categories this will include: plain Greek or natural yoghurt, flavoured Greek or natural yoghurt, custard etc. These generic subcategories will be classified as “high” and “low” sugar products. If the participants selects one or more high sugar products in each category they will be considered a high sugar purchaser.
Each survey condition will include three hypothetical purchasing tasks: one each for breakfast cereals, yoghurts and non-alcoholic packaged beverages. The products in each hypothetical purchasing scenario are commercially available and products that participants would recognise. Each task will consist of choosing one products from ten alternatives with varying sugar content, labelled with one of seven labelling options (depending on the survey condition) currently used in Australia or internationally or under consideration by the Australian Government for example (but not limited to): (i) Status quo – current Nutrition Information Panel (NIP) (Back of Pack labelling system without added sugar content) (control condition); (ii) added sugars quantified in the NIP (the remaining five conditions will also include a back-of-pack NIP with added sugar content); (iii) Pictorial approaches to convey the amount or types of sugars in a serving of food (teaspoons of sugar); (iv) Chilean-style advisory labels for foods high in added sugars; (v) Health Star Rating (using current algorithm without added sugar)- simple display without panel; (vi) Health Star Rating (using proposed algorithm with added sugar)- simple display without panel; and (vii) Change to statement of ingredients to asterisk ingredients with added sugar. Advisory labels will be displayed on high sugar products only. All other labels will be displayed on every product in the choice set, as relevant. Each participant will be exposed to one treatment condition (sugar labelling intervention or control) and complete the purchasing task in all three food categories.

Participants will not receive any feedback after completing the survey.
Intervention code [1] 317666 0
Behaviour
Intervention code [2] 317996 0
Prevention
Comparator / control treatment
Participants exposed to (i) Status quo – current Nutrition Information Panel (NIP) (Back of Pack labelling system without added sugar content)
Control group
Active

Outcomes
Primary outcome [1] 324032 0
The proportion of high sugar products purchased will be assessed using study specific hypothetical food purchasing task questions. “High” sugar products will be classified using the UK Nutrient Profiling Model (foods >6.25g added sugar/100g and beverages >3.13g/100ml). Purchases of high sugar products will be compared between labelling conditions for each food category.
Timepoint [1] 324032 0
Immediately after being exposed to the study intervention
Secondary outcome [1] 383591 0
The mean added sugar content of purchases (g/100g) will be assessed using study-specific hypothetical food purchasing task questions.
To calculate added sugar of products we will use the following decision tree: i) if the ingredients list includes added/free sugars only then the total sugars will be considered added sugars; ii) if the ingredients list includes a mixture of added sugars and intrinsic sugars then we will allocate added sugar as a percentage of total sugar content, based on the percentage added sugar content of a similar generic product in AUSNUT database. We will use AUSNUT “free sugars” content to calculate this. For water-based beverages we will assume that all sugars are added sugars. For fruit juices, we will select branded drinks that provide the percentage of juice the product so we can calculate added sugar content.
Purchases will be compared between labelling conditions for each food category.
.
Timepoint [1] 383591 0
Immediately after being exposed to the study intervention
Secondary outcome [2] 383593 0
The mean Health Star Rating (from 0.5 to 5) of purchases, will be assessed using study-specific hypothetical food purchasing task questions. Health Star Rating will be derived using modifications to the publicly available calculator of the HSR algorithm. To calculate the modified Health Star Rating including added sugar, we will use the UK Nutrient Profiling Model scale for 10% added sugar intake. Purchases will be compared between labelling conditions for each food category.
Timepoint [2] 383593 0
Immediately after being exposed to the study intervention
Secondary outcome [3] 383594 0
The proportion of Five Food Group (healthy) and discretionary (unhealthy) foods purchased will be assessed using study-specific hypothetical food purchasing task according to Australian Dietary Guidelines. Purchases will be compared between labelling conditions for each food category
Timepoint [3] 383594 0
Immediately after being exposed to the study intervention

Eligibility
Key inclusion criteria
-Australian residents
-18 years or older
-Access to a computer and internet connection to complete the survey
-Regular (at least once a month or more) purchasers of breakfast cereal, yoghurt and non- alcoholic pre-packaged drinks for themselves or their household
-Completes at least one supermarket shop per month for their household
-Lives with at least one child <18 years

We will also apply the following recruitment quota:
-At least 50% of participants will be considered high sugar purchases. To categorise participants into high sugar purchasers and low sugar purchasers they will be asked to indicate whether they purchase at least once a month for themselves or their household high sugar yoghurt, breakfast cereal and non-alcoholic packaged drinks (e.g. flavoured yoghurts, kids cereals). If the participants select one or more high sugar products in each category, they will be considered a high sugar consumer
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
None

Study design
Purpose of the study
Prevention
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Eligible participants who agree to participate will be randomised to one of seven treatment groups. The treatment, order of tasks, and order of alternatives presented in each task, will all be randomised.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Participants will not be allocated to intervention groups based on current purchasing habits. current purchasing habits will be used to determine overall sample composition only. After screening, simple randomisation will occur via the online survey platform to one of the seven treatment groups
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint/s
Statistical methods / analysis
Primary outcome:
The differences in the proportion of high sugar products among intended purchases across treatment groups which will be examined using logistic regression analyses. “High” sugar products will be classified using the UK Nutrient Profiling Model (foods >6.25g added sugar/100g and beverages >3.13g/100ml).

Secondary outcomes:
The differences between treatment groups in overall intended purchases by (i) added sugar content (g/100g); (ii) Health Star Rating (from 0.5 to 5); and (iii) percentage of Five Food Group (healthy) and discretionary (unhealthy) foods according to Australian Dietary Guidelines, which will be analysed using logistic or linear regression, as appropriate.

Sample size calculations:
The overall number of participants has increased to 2,633 in this trial, 352 participants per 7 treatment groups (from 144). The required sample size was recalculated using data from the first 1000 participants recruited. This indicated effect sizes were smaller than originally predicted based on previous studies. Sample size of 2,464 would give power equal to 0.8, alpha equal to 0.0083 (Bonferroni for 6 comparisons of each treatment group to control), to detect 13% difference compared to control (p1 equal to 0.5, p2 equal to 0.37). An additional 140 participants will be required due to an error in previous data collection. We will also assume that data from 2% of newly recruited participants will not be usable, resulting in a final sample size of 2,633. This is to ensure that the results we obtain in the study is more representative of the sample population and to correct an error in sampling and a picture used in treatment group three (pictorial approaches to convey the amount or types of sugars in a serving of food). This will increase the accuracy of the results of the study and correct an error made in the initial power calculation. Further we have also factored to recruit extra participants as a number of participants will likely be removed during the survey data cleaning stage (approx. 2%).

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
7/09/2020
Actual
1/09/2020
Date of last participant enrolment
Anticipated
22/02/2021
Actual
13/02/2021
Date of last data collection
Anticipated
22/02/2021
Actual
13/02/2021
Sample size
Target
2633
Accrual to date
Final
2565
Recruitment in Australia
Recruitment state(s)
ACT,NSW,NT,QLD,SA,TAS,WA,VIC

Funding & Sponsors
Funding source category [1] 305342 0
University
Name [1] 305342 0
Deakin University
Country [1] 305342 0
Australia
Primary sponsor type
Individual
Name
Miranda R Blake
Address
Deakin University
Faculty of Health
221 Burwood Hwy,
Burwood VIC 3125
Country
Australia
Secondary sponsor category [1] 306337 0
None
Name [1] 306337 0
Address [1] 306337 0
Country [1] 306337 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 305675 0
The Deakin University Human Research Ethics Committee (DUHREC)
Ethics committee address [1] 305675 0
Ethics committee country [1] 305675 0
Australia
Date submitted for ethics approval [1] 305675 0
27/05/2020
Approval date [1] 305675 0
06/07/2020
Ethics approval number [1] 305675 0
HEAG-H 115_2020

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 101186 0
Dr Miranda R Blake
Address 101186 0
Deakin University
Faculty of Health
221 Burwood Hwy
Burwood, VIC 3125
Country 101186 0
Australia
Phone 101186 0
+61 3 924 68487
Fax 101186 0
Email 101186 0
miranda.blake@deakin.edu.au
Contact person for public queries
Name 101187 0
Miranda R Blake
Address 101187 0
Deakin University
Faculty of Health
221 Burwood Hwy
Burwood, VIC 3125
Country 101187 0
Australia
Phone 101187 0
+61 3 924 68487
Fax 101187 0
Email 101187 0
miranda.blake@deakin.edu.au
Contact person for scientific queries
Name 101188 0
Miranda R Blake
Address 101188 0
Deakin University
Faculty of Health
221 Burwood Hwy
Burwood, VIC 3125
Country 101188 0
Australia
Phone 101188 0
+61 3 924 68487
Fax 101188 0
Email 101188 0
miranda.blake@deakin.edu.au

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
Yes
What data in particular will be shared?
Data may be shared with other researchers and re-used for further research relating to food retail research, beyond the current research project specified.
When will data be available (start and end dates)?
The data will be available for at least 5 years from the date of final publication of results (likely 2021 to 2026).
Available to whom?
The research team and other researchers requesting the data
Available for what types of analyses?
The data may be used for further analysis that is related to food retail research, beyond the current research project specified
How or where can data be obtained?
The data will be made available to other researchers upon request and at the discretion of the research team if they deem it relevant to food retail research. The interested party will be required to contact the principal investigator via email (miranda.blake@deakin.edu.au) or phone (+61 3 924 68487) in order to obtain the data.


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
SourceTitleYear of PublicationDOI
EmbaseExploring the effects of added sugar labels on food purchasing behaviour in Australian parents: An online randomised controlled trial.2022https://dx.doi.org/10.1371/journal.pone.0271435
N.B. These documents automatically identified may not have been verified by the study sponsor.