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Trial registered on ANZCTR


Registration number
ACTRN12619001558112
Ethics application status
Approved
Date submitted
31/10/2019
Date registered
12/11/2019
Date last updated
12/11/2019
Date data sharing statement initially provided
12/11/2019
Type of registration
Retrospectively registered

Titles & IDs
Public title
The effect of a 14-day intervention to reduce sugar cravings in adults
Scientific title
The effect of a 14-day intervention to reduce sugar cravings in adults
Secondary ID [1] 299669 0
Nil known
Universal Trial Number (UTN)
U1111-1243-0887
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Sugar intake 315008 0
Condition category
Condition code
Metabolic and Endocrine 313347 313347 0 0
Normal metabolism and endocrine development and function

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Participants will be randomly allocated to either the control arm or the experimental arm of the study. Subjects and the researcher team will both be blinded to which arm participants are on. The study procedure will last 14 days.

Participants allocated to the experimental group will take:
- An oral tablet containing 4mg of Gynmena sylvestre 3 times per day (between meals) for 14 days (the effects of one gymnema-containing tablet last between 30-60 min)

- A water soluble powder containing fibre, vitamins and minerals (containing: vitamin D as cholecalciferol - 8.33micrograms; thiamin - 3.33mg; vitamin B6 as pyridoxine HCl - 3.33mg; vitamin B12 as cyanocobalamin - 13.33micrograms; Magnesium as magnesium citrate - 66.7mg; zinc as zinc aspartate - 6.67mg and chromium as chromium picolinate - 266.7micrograms) that participants will prepare into a beverage using a drink of their choice once per day before their first meal.

- Follow a provided healthy eating booklet (Eat, Treat, Delete) written by Harley Pasternak.

Adherence will be recorded by participants as they complete a logbook indicating whether they consumed the Gymnema containing tablet and the time this was consumed. They will also record whether they consumed the vitamin and fibre sachet and the time this was consumed. Participants will be asked to return packaging and unconsumed tablets and sachets on their 2nd visit to the sensory lab.

Participants will then undergo a maintenance phase for a further 14 days where they will stop taking the study products and return to there usual habits. At the end of this 14 day period (29 days post commencement of the study) participants will return to the lab and complete the questionnaires relating to the study.

All participants will undergo evaluation at the sensory laboratory twice: the day prior to starting the study procedure (day 0); the day after finishing the study procedure (day 15).

The procedure for the first two lab visits is as follows:

Upon arrival participants will be provided with a standard serve (22g, 438kJ) packet of Grain waves (wholegrain corn chips) each to reduce hunger (45 min prior to testing). During the 45 minutes prior to the sensory testing, participants will then complete a Food Frequency Questionnaire, Motivation questionnaire, Leeds Sleep questionnaire and body composition measures and demographic questionnaire. Demographic questionnaire will be completed during visit 1 only.


Participants will record their hunger and desire for sugar-sweetened product (confectionery). They will then consume a small standardised serving (13g) of their favourite confectionery (from 6 popular brands; which will be provided by the research team), and we will record pleasantness ratings as well as desire for consuming a second serving.

The research assistant will then give participants the gymnema-containing tablet (4mg gymnema sylvestre per tablet) or isocaloric placebo, and asked to ingest the product. Participants and research assistants will be blinded to the tablets provided. Participants will be given the gymnema-containing tablet if they are in the experimental group and the placebo if they are in the control group for this acute, sensory testing portion of the study.

Participants will then rate their desire for another serving (i.e. 13 g) of their preferred confectionery and will be offered up to five servings, which will be given one after the other (after consumption, they will be given 1 minute before selecting a subsequent serving). They will be asked to rate desire for consuming another serving and pleasantness of the confectionery after each serving has been consumed.

If an offering is accepted, it will be consumed and perceptual ratings will be recorded. If an offering is declined, testing and data collection for that participant will end.

Outcomes relating to the acute effects of the gymnema-containing mint/tablet (i.e. pleasantness, desire) refer to acute consumption of the mint/tablet as a comparison of their results at day 0 and day 15 during sensory testing. This will be given to them by the research assistant at these times. Participants in the experimental group will receive the gymnema-containing tablet at the sensory testing in addition to taking the gymnema-containing tablet 3 times per day for 14 days (Study days 1-14). Participants receiving the placebo will take this both during sensory testing and 3 times per day for 14 days (study days 1-14).

At lab visit 3 (study day 29) participants will not undergo sensory testing but will complete the study questionnaires and body composition measures i.e. Food Frequency Questionnaire, Habitual beverage intake questionnaire (BEVQ-15), Motivation questionnaire, Leeds Sleep Evaluation Questionnaire.
Intervention code [1] 315930 0
Treatment: Other
Comparator / control treatment
Participants assigned to the control group will receive an isocaloric placebo oral tablet to take three times per day between meals as per the experimental group procedure. This is a tablet of the same composition as the gymnema containing tablet without the gymenma (i.e. ingredients for this mint/tablet are sorbitol, natural and artificial flavour and magnesium stearate).

The control group participants will receive a sachet containing a placebo carbohydrate mixture (without the fibre, vitamins and minerals) which they will also prepare by pouring the contents into any beverage.
Participants will receive the New Zealand Ministry of Health booklet "Healthy eating, active living" (aimed at healthy eating for New Zealand adults) in place of the "Eat, Treat, Delete" guide
Control group
Placebo

Outcomes
Primary outcome [1] 321833 0
Adherence to the 14-day programme: consumption of all gymnema containing tablets, consumption of fibre, vitamin and mineral sachet. Following of the Eat, Treat and Delete guide.
Timepoint [1] 321833 0
14 days post commencement of the intervention participants will return to the laboratory packaging and unconsumed tablets, and sachets. Participants will also record whether they consumed the tablets and the times each of these were taken in a log book which will be returned to the research assistants.
Secondary outcome [1] 376401 0
Number of servings of sugar-sweetened confectionery consumed post ingestion of gymnema sylsvestre-containing mint/tablet.

The research assistant will count how many servings are consumed by the participant at each visit (and verify consumption by the empty confectionery wrapper).
Timepoint [1] 376401 0
Acute (within 30-40 min of consuming the mint/tablet) during the lab visits on days 0 and 15.
Secondary outcome [2] 376402 0
Perceived hunger level
Timepoint [2] 376402 0
Assessed using Likert scale within 30-40 min of consuming the mint/tablet containing gymnema sylvestre during the lab visits on days 0 and 15.
Secondary outcome [3] 376403 0
Effect of body fat percentage on changes to amount of confectionery eaten and sensory ratings, following consumption of gymnema sylvestre-containing mint/tablet
Timepoint [3] 376403 0
Will be assessed using bio-electrical impedance analysis (BIA) at day 0 (prior to starting the 14 day intervention), day 15 and day 29.
Secondary outcome [4] 376404 0
Effect of 14-day study intervention (consumption of gymnema containing tablet and sachet) on changes to Body Mass Index
Timepoint [4] 376404 0
Will be assessed using a stadiometer and calibrated scales on a bio-electrical impedance analysis machine (BIA) at day 0 (prior to starting the 14 day intervention), day 15 and day 29 post commencement of the intervention
Secondary outcome [5] 376405 0
Effect of 'super-tasting' ability on changes to amount of confectionery eaten and sensory ratings, following consumption of gymnema sylvestre-containing mint/tablet.

Participants’ taster status will be determined using propylthiouracil (PROP) solution. Participants will be asked to taste this solution and indicate the perceived bitterness intensity. This will be used to classify subjects as either super-tasters, tasters or non-tasters. This information will be useful in interpreting the sensory data based on individual differences in taste sensitivity.
Timepoint [5] 376405 0
Will be assessed using PROP prior to consuming gymnema-containing mint/tablet
Secondary outcome [6] 376406 0
Effect of having a 'sweet tooth' (assessed using food frequency questionnaire; composite analysis) on changes to amount of confectionery eaten and sensory ratings, following consumption of gymnema sylvestre-containing mint/tablet
Timepoint [6] 376406 0
A food frequency questionnaire will be used (composite analysis) to assess 'sweet tooth' prior to consuming gymnema-containing mint/tablet
Secondary outcome [7] 376407 0
Desire to eat another sugar-sweetened product (confectionery)
Timepoint [7] 376407 0
Will be assessed using a Likert scale within 30-40 minutes of consuming gymnema-containing mint/tablet during the lab visits on days 0 and 15
Secondary outcome [8] 376408 0
Pleasantness ratings of confectionary
Timepoint [8] 376408 0
Will be assessed using a Likert scale within 30-40 minutes of consuming gymnema-containing mint/tablet during the lab visits on days 0 and 15
Secondary outcome [9] 376598 0
Effect of 14-day study intervention (consumption of gymnema containing tablet and sachet) on changes to body fat percentage
Timepoint [9] 376598 0
Will be assessed using bio-electrical impedance analysis (BIA) at day 0 (prior to starting the 14 day intervention), day 15 and day 29 post commencement of the intervention

Eligibility
Key inclusion criteria
Healthy adults aged 18-45 years old
Non-smoking
Non-diabetic

English-speaking
Minimum age
18 Years
Maximum age
45 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Known allergies to gymnema sylvestre
Gluten intolerance
Having a pacemaker

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)
Allocation will be undertaken by staff member not involved the current study. This staff member will hold the allocation schedule on a separate site.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation using randomisation table created by computer software (using http://randomization.com/).
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s

The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint(s)
Efficacy
Statistical methods / analysis
Statistical analyses will be completed using the Statistical Package for the Social Sciences (SPSS, Chicago, IL). All data will be inspected visually and statistically for normality. Normally distributed data will be described using mean ± SD and non-normally distributed data using median and ranges. Two-way analysis of variance (ANOVA) will be used to determine the difference between conditions at each time point evaluated. A suitable post-hoc test (Holm-Bonferroni adjusted paired t-test) will be used to ascertain differences between time points. Pearson’s correlation will be used to examine relationships between outcome measures. P<0.05 will be considered indicative of statistical significance. Furthermore, effect sizes (Cohen’s d) will be calculated (where applicable) to show practical significance.

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] 21970 0
New Zealand
State/province [1] 21970 0
Auckland

Funding & Sponsors
Funding source category [1] 304145 0
Commercial sector/Industry
Name [1] 304145 0
Nu Brands Ltd
Address [1] 304145 0
936 N Laurel Avenue
Los Angeles CA 90046
USA
Country [1] 304145 0
United States of America
Primary sponsor type
University
Name
Massey University
Address
Private Bag 11222
Palmerston North 4442
Country
New Zealand
Secondary sponsor category [1] 304381 0
None
Name [1] 304381 0
Address [1] 304381 0
Country [1] 304381 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 304625 0
Massey University Human Ethics Committee
Ethics committee address [1] 304625 0
Massey University
Private Bag 11222
Palmerston North 4442
Ethics committee country [1] 304625 0
New Zealand
Date submitted for ethics approval [1] 304625 0
11/09/2019
Approval date [1] 304625 0
11/10/2019
Ethics approval number [1] 304625 0
MUHEC NOR 19/52

Summary
Brief summary
Gymnema sylvestre (gymnema) is a plant-derived sweetness inhibitor which impairs one’s ability to taste sugar by temporarily blocking sweet receptors on the tongue. It is therefore a taste modulator which interferes with the ability of sucrose to activate the sweet receptors on the tongue leading to a decrease in sweetness perception without affecting the other basic tastes. This effect is reversible and lasts between 30-60 minutes. A mint containing gymnema has been developed by a commercial entity (based in US), and is part of a ’14-day sugar reset dietary intervention’ designed to reduce cravings for sugar-sweetened foods and beverages. The 14day intervention also includes daily consumption of a powder containing prebiotic fibre, vitamins and minerals, and adherence to a food guide (“eat, treat, delete”). The overall aim is to assess the effectiveness of a 14-day supplement and behaviour intervention to reduce sugar cravings in healthy adults. We wish to explore the perception of the intervention, as well adherence to the programme, and investigate whether (sugar-containing) product use and related food behaviours are maintained following the completion of the 14-day programme. We will also explore associations with dietary intake of sweet-tasting foods (food frequency questionnaire), body composition (BIA), and if there are any differences in responses between ‘super-tasters’ and normal tasters.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 97634 0
A/Prof Ajmol Ali
Address 97634 0
School of sport, Exercise and Nutrition
Massey University
Private Bag 102904
North Shore, Auckland
Country 97634 0
New Zealand
Phone 97634 0
+64 9 213 6414
Fax 97634 0
Email 97634 0
a.ali@massey.ac.nz
Contact person for public queries
Name 97635 0
A/Prof Ajmol Ali
Address 97635 0
School of sport, Exercise and Nutrition
Massey University
Private Bag 102904
North Shore, Auckland
Country 97635 0
New Zealand
Phone 97635 0
+64 9 213 6414
Fax 97635 0
Email 97635 0
a.ali@massey.ac.nz
Contact person for scientific queries
Name 97636 0
A/Prof Ajmol Ali
Address 97636 0
School of sport, Exercise and Nutrition
Massey University
Private Bag 102904
North Shore, Auckland
Country 97636 0
New Zealand
Phone 97636 0
+64 9 213 6414
Fax 97636 0
Email 97636 0
a.ali@massey.ac.nz

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
Only mean and standard deviation data will be available (via the subsequent publications)
What supporting documents are/will be available?
No other documents available
Summary results
No Results