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Trial registered on ANZCTR


Registration number
ACTRN12622001023741
Ethics application status
Approved
Date submitted
18/07/2022
Date registered
21/07/2022
Date last updated
21/07/2022
Date data sharing statement initially provided
21/07/2022
Type of registration
Retrospectively registered

Titles & IDs
Public title
The effect of Gymnema sylvestre-containing mints on sugar consumption in adults with a sweet tooth - the Liberate From Sugar, Mate! study
Scientific title
The effect of Gymnema sylvestre-containing mints on sugar consumption in adults with a sweet tooth - the Liberate From Sugar, Mate! study
Secondary ID [1] 307603 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Overweight 327063 0
Diabetes mellitus 327095 0
Obesity 327096 0
Condition category
Condition code
Diet and Nutrition 324220 324220 0 0
Other diet and nutrition disorders
Mental Health 324242 324242 0 0
Studies of normal psychology, cognitive function and behaviour
Metabolic and Endocrine 324257 324257 0 0
Diabetes

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
For an initial 14 days all participants will be treated with a placebo i.e. without the active ingredient. Participants will be required to consume the placebo mint (see below note about mints) three times per day for 14 days, at specified time points (mid-morning, mid-afternoon, post-dinner).

Participants will then be randomly allocated into two experimental groups which they will be in for the following 14 days: either the Systematic or Ad-lib groups.

After these 14 days, the participants will undertake the second intervention trial (i.e., “crossover” - if participants were allocated to Systematic intervention for the first 14 days, they will then follow the Ad-lib intervention for the next 14 days.

Intervention B: Systematic intervention
- Materials: Gymnema sylvestre (GS) mints (see below note about mints) compliance diaries
- Procedures / activities: participants will undertake a 14-day GS mint intervention where they are asked to 1) consume the GS mint three times a day at specified time points and 2) complete the compliance diary daily.
- Who will deliver intervention: student dietitians Imogen Nelson and David Hsiao
- Mode of delivery: mints will be provided for participants at visit 2 or 3 (depending on group allocation as per cross over design), and participants will then follow the intervention for 14 days at home.
- Number of times the intervention will be delivered and their duration, intensity or dose: three mints per day for 14 days.
- Location where intervention occurs: participant’s homes.

Intervention C: Ad-lib intervention
- Materials: GS mints (please see below note about mints), compliance diaries
- Procedures / activities: Participants will undertake a 14-day GS mint intervention where they are asked to 1) take GS mints freely at times of their own choosing up to six times a day and 2) complete the compliance diary daily.
- Who will deliver intervention: student dietitians Imogen Nelson and David Hsiao
- Mode of delivery: mints will be provided for participants at visit 2 or 3 (depending on group allocation as per cross over design), and participants will then follow the intervention for 14 days at home.
- Number of times the intervention will be delivered and their duration, intensity or dose: up to six mints per day for 14 days.
- Location where intervention occurs: participant’s homes.

Note about wash out periods: There is no “wash out” period in between the placebo treatment and the first intervention; nor is there one in between the first and second interventions. The same product is being used in both interventions B and C, the participants are just being led to believe they are taking different products. The only thing that differs in reality with interventions B and C is the dosage at which the mints are taken. Because the same product is being used just in different ways, the research team deemed a wash out period unnecessary.

Note about mints: The GS mints contain 4mg GS, 5mg chicory root inulin, in addition to sorbitol, natural and artificial flavour, magnesium stearate and silicon dioxide. They are to be provided by Nu Brands, Inc and are an updated formula of the mints already available online known as Sweetkick mints) The placebo mints are produced and provided by Nu Brands, Inc as well and contain the same identical ingredients EXCEPT for the GS.
All mints are to be taken orally, and all participants will receive instructions on how to take them. The standard operating procedure for taking the mint involves placing it on the tongue and sucking on it while moving it around the tongue as it dissolves so it coats the entire layer of the tongue.


Intervention code [1] 324051 0
Treatment: Other
Intervention code [2] 324052 0
Lifestyle
Intervention code [3] 324053 0
Behaviour
Comparator / control treatment
Intervention A: Placebo intervention
Placebo: isocaloric mint taken in the same fashion as the mints in the Systematic intervention. Cross-over design.
The placebo mint is the same composition as the GS-containing mint but without the GS. Therefore it contains 5mg chicory root inulin, sorbitol, natural and artificial flavour, magnesium stearate and silicon dioxide. It is also produced and provided by Nu Brands, Inc.



Control group
Placebo

Outcomes
Primary outcome [1] 332039 0
Motivations to eat sugar sweetened food as assessed by individual, semi-structured interviews designed for the study with volunteers.
Timepoint [1] 332039 0
Days 0, 15, 30 and 45 after commencement of data collection. In other words, day 0 = baseline; day 15 = after intervention A; day 30 = after intervention B or C; day 45 = final, after crossover to intervention C or B.
Primary outcome [2] 332040 0
Ad-libitum intake of GS-containing mints as assessed by compliance diaries designed for the study.
Timepoint [2] 332040 0
Days 16 - 29 OR days 31 - 44 after commencement of data collection, depending on which group the participants are randomly assigned to as per cross-over design. Compliance diaries will be completed daily on each day of interventions A, B and C (i.e. days 1 - 14, 16 - 29, and 31 - 44)
Primary outcome [3] 332041 0
Changes in food cravings as assessed by a validated food cravings questionnaire called the Food Cravings Questionnaire (Cepeda-Benito, Gleaves, Williams, & Erath, 2000)

Timepoint [3] 332041 0
Days 0, 30 and 45 after commencement of data collection. In other words, day 0 = baseline; day 30 = after intervention B or C; day 45 = final, after crossover to intervention C or B.

Secondary outcome [1] 411970 0
Hunger levels as assessed via Visual Analogue Scales.
Timepoint [1] 411970 0
Days 0, 15 and 30 after commencement of data collection. In other words, day 0 = baseline; day 15 = after intervention A; day 30 = after intervention B or C.
Secondary outcome [2] 411971 0
Changes in body composition (i.e. change in body fat % and change in total body weight) as assessed via bioelectrical impedance (BIA). The BIA being used in this study also weighs body weight (it has a function enabling it to act as a set of digital scales in addition to BIA).
Timepoint [2] 411971 0
Days 0, 30 and 45 after commencement of data collection. In other words, day 0 = baseline; day 30 = after intervention B or C; day 45 = final, after crossover to intervention C or B.
Secondary outcome [3] 412037 0
(Primary outcome): changes in beverage intake as assessed by a beverage intake questionnaire. The beverage intake questionnaire used is called the Brief 15-Item Beverage Intake Questionnaire (BEVQ-15) and is adapted specifically for this study from Hedrick et al.'s original validated BEVQ-15 questionnaire (2001).
Timepoint [3] 412037 0
Days 0, 30 and 45 after commencement of data collection. In other words, day 0 = baseline; day 30 = after intervention B or C; day 45 = final, after crossover to intervention C or B.
Secondary outcome [4] 412038 0
(Primary outcome): changes in food intake as assessed by a food frequency questionnaire. The questionnaire used is called the Food Frequency Questionnaire and is adapted specifically for this study from Mumena & Kutibi's validated Food Frequency Questionnaire (2022)
Timepoint [4] 412038 0
Days 0, 30 and 45 after commencement of data collection. In other words, day 0 = baseline; day 30 = after intervention B or C; day 45 = final, after crossover to intervention C or B.
Secondary outcome [5] 412039 0
Levels of desire for sugar sweetened food as assessed via Visual Analogue Scales.
Timepoint [5] 412039 0
Days 0, 15 and 30 after commencement of data collection. In other words, day 0 = baseline; day 15 = after intervention A; day 30 = after intervention B or C.
Secondary outcome [6] 412040 0
Self-reported pleasure from sugar sweetened food as assessed via Visual Analogue Scales.
Timepoint [6] 412040 0
Days 0, 15 and 30 after commencement of data collection. In other words, day 0 = baseline; day 15 = after intervention A; day 30 = after intervention B or C.

Eligibility
Key inclusion criteria
Eligible participants for the study 1) have a self-reported sweet tooth, 2) can come onto the Massey University Albany campus for four separate visits, 3) are in general good health.

Minimum age
18 Years
Maximum age
60 Years
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
- Gluten allergies (because snacks provided are not gluten free)
- Sorbitol intolerances (because the GS mints contain sorbitol)
- Do not eat chocolate (because all confectionary offered as part of testing contains chocolate)
- Pregnant
- Has a pace maker
- Current smokers
- Are affected by a condition that affects the ability to taste food (a health screening questionnaire will be used to ensure eligibility)
- Are affected by health conditions including but not excluded to diabetes and heart disease (a health screening questionnaire will be used to ensure eligibility)
- Compromised capacity to consent


Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Central randomisation by computer.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation using computer software.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s
The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Crossover
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
A G*power calculation on SPSS was used to determine the sample size. A single power value of 0.05, an effect size of 0.15, a significance level of 0.05 and a sample size of 23 (from a previous study by Nobel, Baker & Louliss, 2017) produced an initial sample size of 30. Cohen (1988) indicates that a power of 0.80 is required to reflect large effects (r = 0.5). Given this the researchers have selected a sample size of 40 to enable them to see medium effects (r = 0.3). This is an increase of 10 participants from the originally calculated sample size, which will also account for some potential drop outs that may occur during the progression of the study.


Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment outside Australia
Country [1] 24900 0
New Zealand
State/province [1] 24900 0
Auckland

Funding & Sponsors
Funding source category [1] 311872 0
University
Name [1] 311872 0
Massey University
Country [1] 311872 0
New Zealand
Primary sponsor type
University
Name
Massey University
Address
Massey University (East Precinct), Albany Expressway (SH17), Albany, Auckland 0632
Country
New Zealand
Secondary sponsor category [1] 313348 0
None
Name [1] 313348 0
Address [1] 313348 0
Country [1] 313348 0
Other collaborator category [1] 282367 0
Commercial sector/Industry
Name [1] 282367 0
Nu Brands, Inc
Address [1] 282367 0
936 N. Laurel Ave Los Angeles, California, 90046
Country [1] 282367 0
United States of America

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 311308 0
Massey University Southern A committee
Ethics committee address [1] 311308 0
Ethics committee country [1] 311308 0
New Zealand
Date submitted for ethics approval [1] 311308 0
26/04/2022
Approval date [1] 311308 0
15/07/2022
Ethics approval number [1] 311308 0
N/A

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

Contacts
Principal investigator
Name 120654 0
Mr David Hsiao
Address 120654 0
Massey University (East Precinct), Albany Expressway (SH17), Albany, Auckland 0632
Country 120654 0
New Zealand
Phone 120654 0
+64 0211148776
Fax 120654 0
Email 120654 0
Contact person for public queries
Name 120655 0
David Hsiao
Address 120655 0
Massey University (East Precinct), Albany Expressway (SH17), Albany, Auckland 0632
Country 120655 0
New Zealand
Phone 120655 0
+64 0211148776
Fax 120655 0
Email 120655 0
Contact person for scientific queries
Name 120656 0
David Hsiao
Address 120656 0
Massey University (East Precinct), Albany Expressway (SH17), Albany, Auckland 0632
Country 120656 0
New Zealand
Phone 120656 0
+64 0211148776
Fax 120656 0
Email 120656 0

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


What supporting documents are/will be available?

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.