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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Date data sharing statement initially provided
Date results information initially provided
Type of registration
Retrospectively registered

Titles & IDs
Public title
A social media nutrition promotion program to improve calcium intakes in young adults
Scientific title
Assessing Calcium Knowledge and Intake in Young Adults Via Social Media and Text Messages: Randomized Controlled Trial
Secondary ID [1] 300144 0
Universal Trial Number (UTN)
Trial acronym
CAN-Do: CAlcium Nutrition-Dietary Opportunities
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Calcium intake 315674 0
Condition category
Condition code
Diet and Nutrition 313963 313963 0 0
Other diet and nutrition disorders
Public Health 314304 314304 0 0
Health promotion/education

Study type
Description of intervention(s) / exposure
The 3 arm RCT included two intervention groups (Facebook and Facebook plus text) and one control group. For the Facebook group, educational (educating on calcium-containing food sources and recommended serves) and motivational posts (reminded participants about setting
goals and tracking progress for habit formation, tips for including more calcium) together with cooking videos (recipe videos that provided instructions on how to incorporate calcium in main meals and snacks) were delivered every second day for six weeks. An infographic was used to inform participants of the recommendations and set as the cover photo. The design of these posts applied the COM-B model of behaviour change.

For the Facebook plus text group, on the alternate days when Facebook contact was not delivered, text messages that asked them to set goals, prompted them to engage with the Facebook content and progress their goals. Social support was provided via 2-way text messaging.
The duration was six weeks and the intervention was delivered remotely by a dietitian to the Australian community of young adults. The daily usage was at the participant’s discretion. The location was to the persons Facebook account or mobile phone (for those receiving text messages). Fidelity was assessed by number of replies to text messages and views of Facebook posts
Intervention code [1] 316413 0
Intervention code [2] 316414 0
Treatment: Other
Intervention code [3] 316687 0
Comparator / control treatment
Participants in the control group were emailed once with an e-leaflet on calcium and did not receive any continued support on social media. The e-leaflet was created specifically for this study by the research team.
Control group

Primary outcome [1] 322366 0
Change in calcium intake
Self-report questionnaire was adapted from Pasco et al 2000
Timepoint [1] 322366 0
Measured at baseline and after 6 weeks
Secondary outcome [1] 378235 0
The secondary outcomes measured the impact of the intervention on determinants of calcium intake which included knowledge of calcium recommendations and serve sizes, self-efficacy, motivation for consuming calcium-rich foods and habit formation.

1) Knowledge was assessed by participant’s ability to identify sources of calcium, a correct serve of calcium and stating the calcium requirements for their age group using a researcher-designed questionnaire as no validated questionnaire could be found.
Timepoint [1] 378235 0
Measured at baseline and after 6 weeks
Secondary outcome [2] 378956 0
2) A Five Item Likert Scale questionnaire previously validated for other dietary behaviours was adapted to measure self-efficacy for improving calcium-rich food consumption from Ma et al 2002.
Timepoint [2] 378956 0
Measured at baseline and after 6 weeks
Secondary outcome [3] 378957 0
3) Autonomous and controlled motivation for consumption of calcium was measured using a Self-Regulation Questionnaire adapted from Coa et al 2016 and Levesque et al 2007.
Timepoint [3] 378957 0
Measured at baseline and after 6 weeks
Secondary outcome [4] 378958 0
4) Habit formation for calcium intake was measured using the validated Four Item Seven Point Scale Self-Report Behavioural Automaticity Index which was adapted from Gardner et al 2012
Timepoint [4] 378958 0
Measured at baseline and after 6 weeks

Key inclusion criteria
Anyone aged 18 to 25 years and owning a Facebook account and smartphone
Minimum age
18 Years
Maximum age
25 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Anyone who completed a nutrition course or currently undertaking a nutrition course on the basis of their high existing level of nutrition knowledge. Additionally, any participants with a food allergy, known lactose intolerance or currently taking calcium supplements (but not multivitamins) or eating disorders was excluded.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation involved contacting the holder of the allocation schedule who was “off-site” or at central administration site- the randomisation was performed by two independent researchers who were not study investigators.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation using a randomisation table created by computer software (i.e. computerised sequence generation)- a randomised sequence generation was used to allocate the participants.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?

Intervention assignment
Other design features
3 arm RCT- two intervention groups and one control group
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
This was a three-arm parallel trial with a 1:1:1 allocation ratio. The three groups were Facebook intervention (Facebook); Facebook intervention plus text messages (Facebook plus text); and e-leaflet containing information on calcium intake (Control). Sample size was determined using GPower a statistical power analysis software. To detect a mean difference of 125 mg calcium intake with P= 0.05 and 90% power assuming a standard deviation of 259 mg, a sample size of 45 was required per arm and increased to 75 to allow for 40% drop out.

To account for all participants, an intention to treat analysis with multiple imputations for missing values was used. This meant that all participants who were randomised at the start of the trial were retained for analyses. Due to the large amount of missing data, 10 imputed datasets were created based on gender, SEIFA (Socioeconomic Index), cooking frequency per week and baseline intake of primary (milk and calcium intake) and secondary outcomes (knowledge, self-efficacy, motivation and habit) using Stata version 13.1.
The primary outcome of change in milk intake, which was categorical in number of cups, was compared between three groups using a logistic regression model adjusted for gender, SEIFA, cooking frequency, baseline calcium (non-milk) baseline knowledge, baseline self-efficacy, baseline motivation and baseline habit. The quantitative values for change in calcium intake from other dietary sources were compared using linear regression as were the variables for the secondary outcomes of knowledge score, self-efficacy for change score, motivation and habit score adjusted for gender, SEIFA, cooking frequency, baseline calcium intake, baseline knowledge, self-efficacy, motivation and habit. The distribution of missing outcome data at both time points was investigated using counts and percentages across all sociodemographic variables. Furthermore, separate general estimating equation (GEEs) models for binary data were used to investigate any relationships between sociodemographic variables and missingness in each outcome, adjusting for other sociodemographic variables.

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)

Funding & Sponsors
Funding source category [1] 304579 0
Name [1] 304579 0
The University of Sydney
Address [1] 304579 0
Charles Perkins Centre, The University of Sydney
Camperdown 2006
NSW Australia
Country [1] 304579 0
Primary sponsor type
The University of Sydney
The University of Sydney
Camperdown 2006
NSW Australia
Secondary sponsor category [1] 305049 0
Name [1] 305049 0
Address [1] 305049 0
Country [1] 305049 0

Ethics approval
Ethics application status
Ethics committee name [1] 305005 0
The University of Sydney Human Research Ethics Committee, The University of Sydney HREC 1
Ethics committee address [1] 305005 0
The University of Sydney Human Research Ethics Committee (HREC)
Level 2 Margaret Telfer Building
The University of Sydney
NSW 2006
Ethics committee country [1] 305005 0
Date submitted for ethics approval [1] 305005 0
Approval date [1] 305005 0
Ethics approval number [1] 305005 0

Brief summary
This project will recruit young adults (18-25 years) to a social media intervention that aims to improve calcium intake of young adults. Our previous research indicates most fail to meet the recommended dietary intake. The CAN-DO (CAlcium Nutrition- Dietary Opportunities) study will have three arms, one intervention group will be exposed to Facebook; one will be exposed to Facebook with text messages groups while the control group will be emailed once with an e-leaflet. Participants will be asked to complete a baseline and end of intervention questionnaire to assess change in dietary calcium intake.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 98938 0
Ms Anika Rouf
Address 98938 0
Level 4 East, Charles Perkins Centre
The University of Sydney
NSW 2006
Country 98938 0
Phone 98938 0
+61 2 8627 4704
Fax 98938 0
+61 2 8627 1605
Email 98938 0
Contact person for public queries
Name 98939 0
Prof Margaret Allman-Farinelli
Address 98939 0
Level 4 East, Charles Perkins Centre
The University of Sydney
NSW 2006
Country 98939 0
Phone 98939 0
+61 2 9036 7045
Fax 98939 0
+61 2 8627 1605
Email 98939 0
Contact person for scientific queries
Name 98940 0
Ms Anika Rouf
Address 98940 0
Level 4 East, Charles Perkins Centre
The University of Sydney
NSW 2006
Country 98940 0
Phone 98940 0
+61 2 8627 4704
Fax 98940 0
+61 2 8627 1605
Email 98940 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No/undecided IPD sharing reason/comment
Data sharing was not approved in ethics
What supporting documents are/will be available?
No other documents available
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Other publication details
Citation type [1] 6482 0
Citation/DOI/link/details [1] 6482 0
The citation will be used for the following PhD thesis:
Anika Rouf, Investigating the use of social media to improve calcium intake of young adults, The University of Sydney, November 2019
Attachments [1] 6482 0
Results – basic reporting
Results – plain English summary