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Trial registered on ANZCTR


Registration number
ACTRN12624000259549
Ethics application status
Approved
Date submitted
19/01/2024
Date registered
15/03/2024
Date last updated
15/03/2024
Date data sharing statement initially provided
15/03/2024
Type of registration
Retrospectively registered

Titles & IDs
Public title
The effectiveness of a dietary challenge for improving dietary intake in Australian adults.
Scientific title
Assessing the effectiveness of a dietary intake challenge and the validity of a behaviour change readiness index for predicting beverage intake in Australian adults.
Secondary ID [1] 311373 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Obesity 332644 0
Self-efficacy 332645 0
Condition category
Condition code
Diet and Nutrition 329349 329349 0 0
Other diet and nutrition disorders
Public Health 329350 329350 0 0
Other public health
Mental Health 329351 329351 0 0
Studies of normal psychology, cognitive function and behaviour

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Part 1 of the study involved completing an initial screening survey. Participants were asked to complete a series of questions about their health behaviours (including dietary intake) and their readiness to change such behaviours. They were also asked several behavioural and psychological measures that formed predictors for participation in the intervention (the second phase of the study). Participants who met the criteria for sweet treat intake on more than 5 days per week were invited to participate in the second phase of the study. They were asked to contact the study team to indicate their interest and provide their initials and last 3 digits of their phone number to facilitate data matching. Those who contacted the team were sent a second information sheet and asked to indicate consent via email. Part 1 occurred within a couple of weeks of part 2.
Part 2: The intervention itself was designed to be as straightforward as possible, with minimal participant commitment needed to initiate it. Participants were provided an online visual tile explaining the challenge aim. the message was “Try to eat less sweet snacks including biscuits, buns, cakes, muffins, doughnuts, lollies, and chocolate, for the next four weeks”. Participants were instructed to select any way that worked for them, but suggested tactics including reducing the frequency (i.e., cutting out all or some of these foods), reducing the portion size (i.e., amount eaten each time), having “sweet treat free days”, and making healthy swaps (e.g., fruit or low-fat yoghurt). No other support was provided to participants. Participants were instructed to reduce sweet treat intake for 4-weeks, but a specific amount was not indicated as any reduction in discretionary food intake is beneficial for working toward meeting the Australian Dietary Guidelines.

Participants used an Ecological Momentary Assessment (EMA) smartphone application to record their sweet treat intake intake once daily as well as their mood twice daily. No other direct contact was made with the participants over the four weeks, other than to respond to enquiries and to send links to complete follow-up surveys (i.e,, start of challenge, week 2, week 4).

A key outcome of the study involved validating the CSIRO behaviour change readiness index, which comprised psychological and experiential predictors of initial interest and committed intention to change a health behaviour, as well as behaviour change success. This will be done by assessing the utility of the index for predicting successful short-term behaviour change outcomes in the dietary domain (i.e., sweet treat intake), but also to better understand the associations and strengths of relevant factors to refine this tool into a succinct survey. Thus, the study focused on predicting behavioural outcomes rather than improving health behaviours. The validation of the index involved participants from part 1 of the study. We further refined this tool based on a previous study conducted in a different dietary domain (Assessing the effectiveness of a water intake challenge and the validity of a behaviour change readiness index for predicting beverage intake in Australian adults.).
Intervention code [1] 327815 0
Lifestyle
Intervention code [2] 327816 0
Behaviour
Comparator / control treatment
No control group.
Control group
Uncontrolled

Outcomes
Primary outcome [1] 337167 0
Discretionary food intake
Timepoint [1] 337167 0
Screening and Week 4 (end of treatment
Secondary outcome [1] 430940 0
Coping self-efficacy
Timepoint [1] 430940 0
Baseline and week 4 (end of treatment)
Secondary outcome [2] 430941 0
Habit
Timepoint [2] 430941 0
Baseline and week 4 (end of treatment)
Secondary outcome [3] 430942 0
Daily Hassles/uplifts
Timepoint [3] 430942 0
Baseline and Week 4 (end of treatment)
Secondary outcome [4] 430943 0
Executive function
Timepoint [4] 430943 0
Baseline and end of week 4 (treatment)
Secondary outcome [5] 430944 0
Self-regulatory failure
Timepoint [5] 430944 0
Baseline, Week 2 (mid-point) and Week 4 (end of treatment)
Secondary outcome [6] 430945 0
Behavioural self-efficacy
Timepoint [6] 430945 0
Baseline and Week 4 (end of treatment scale)
Secondary outcome [7] 430946 0
Behavioural intention
Timepoint [7] 430946 0
Baseline and Week 4 (end of treatment)
Secondary outcome [8] 430947 0
Stage of change
Timepoint [8] 430947 0
Baseline and Week 4 (end of treatment)
Secondary outcome [9] 430948 0
Vitality
Timepoint [9] 430948 0
Baseline and week 4 (end of treatment)
Secondary outcome [10] 430949 0
Stress
Timepoint [10] 430949 0
Baseline, week 2 (mid-point) and week 4 (end of treatment)
Secondary outcome [11] 430954 0
Self-Evaluation and feedback survey
Timepoint [11] 430954 0
Week 2 (mid-point)
Secondary outcome [12] 430955 0
Subjective Wellbeing
Timepoint [12] 430955 0
Screening and week 4 (end of treatment)
Secondary outcome [13] 430956 0
Sweet snack intake
Timepoint [13] 430956 0
Daily from baseline to week 4 (end of treatment)
Secondary outcome [14] 430957 0
Mental energy
Timepoint [14] 430957 0
Daily from baseline to week 4 (end of treatment)

Eligibility
Key inclusion criteria
Part 1: Initial screening survey
• 18 years or older
• Perceived good comprehension of English.
• Residing in Australia

Part 2: 4-week intervention
• Completed inital screening survey
• Met following screening criteria based on survey responses: eat cakes/biscuits/buns/donuts or chocolate/lollies most days a week
• Willing to provide informed consent
• Access to own smartphone and willing to download a free application from app store
• Access to own email address/service
• Minimum iOS 12.0 and Android 5.0 to access the study app
• People who are currently consuming their typical diet, and not in the process of changing their dietary habits
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
• Any self-reported disordered eating
• Participated in "The effectiveness of a water challenge on beverage intake in Australian adults and assessment of the validity of a behaviour change readiness index" study.

Study design
Purpose of the study
Treatment
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Single group
Other design features
Phase
Not Applicable
Type of endpoint/s
Statistical methods / analysis
To predict different stages of behavioural engagement using outcomes collected in the screening survey, we have based our numbers on the minimum amount need for linear analyses using the Early Success group (successfully changing behaviour). Based on participant numbers and engagement from the previous study (The effectiveness of a water challenge on beverage intake in Australian adults and assessment of the validity of a behaviour change readiness index"), we required 4416 people to start the initial screening survey (Part 1). This will leave us with enough people who initially sign-up to the 4-week intervention (i.e., 390).

Our primary analysis will be linear regressions predicting membership to various behavioural stages. This will be supplemented with other descriptive techniques where needed.

Recruitment
Recruitment status
Stopped early
Data analysis
Data analysis is complete
Reason for early stopping/withdrawal
Participant recruitment difficulties
Date of first participant enrolment
Anticipated
Actual
11/05/2023
Date of last participant enrolment
Anticipated
Actual
11/05/2023
Date of last data collection
Anticipated
Actual
9/06/2023
Sample size
Target
390
Accrual to date
Final
92
Recruitment in Australia
Recruitment state(s)
ACT,NSW,NT,QLD,SA,TAS,WA,VIC

Funding & Sponsors
Funding source category [1] 315632 0
Other
Name [1] 315632 0
CSIRO
Country [1] 315632 0
Australia
Primary sponsor type
Other
Name
CSIRO
Address
Gate 13, Kintore Avenue, Adelaide, South Australia 5000
Country
Australia
Secondary sponsor category [1] 317730 0
None
Name [1] 317730 0
Address [1] 317730 0
Country [1] 317730 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 314516 0
The CSIRO Health and Medical Human Research Ethics committee (low risk review panel)
Ethics committee address [1] 314516 0
Ethics committee country [1] 314516 0
Australia
Date submitted for ethics approval [1] 314516 0
21/03/2023
Approval date [1] 314516 0
03/04/2023
Ethics approval number [1] 314516 0
2023_013_LR

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

Contacts
Principal investigator
Name 131858 0
Dr Emily Brindal
Address 131858 0
CSIRO, Gate 13, Kintore Avenue, Adelaide, South Australia, 5000
Country 131858 0
Australia
Phone 131858 0
+61 8 83050633
Fax 131858 0
Email 131858 0
emily.brindal@csiro.au
Contact person for public queries
Name 131859 0
Emily Brindal
Address 131859 0
CSIRO, Gate 13, Kintore Avenue, Adelaide, South Australia, 5000
Country 131859 0
Australia
Phone 131859 0
+61 8 83050633
Fax 131859 0
Email 131859 0
emily.brindal@csiro.au
Contact person for scientific queries
Name 131860 0
Emily Brindal
Address 131860 0
CSIRO, Gate 13, Kintore Avenue, Adelaide, South Australia, 5000
Country 131860 0
Australia
Phone 131860 0
+61 8 83050633
Fax 131860 0
Email 131860 0
emily.brindal@csiro.au

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment


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
No additional documents have been identified.