The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial registered on ANZCTR


Registration number
ACTRN12617000551392
Ethics application status
Approved
Date submitted
12/03/2017
Date registered
19/04/2017
Date last updated
19/04/2017
Type of registration
Retrospectively registered

Titles & IDs
Public title
Carbohydrate taste sensitivity testing in healthy volunteers to determine human oral carbohydrate taste function and its association with food consumption, BMI, and ad libitum consumption of carbohydrate foods
Scientific title
Carbohydrate taste sensitivity testing in healthy volunteers to determine human oral carbohydrate taste function and its association with food consumption, BMI, and ad libitum consumption of carbohydrate foods
Secondary ID [1] 291430 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
obesity 302446 0
Condition category
Condition code
Diet and Nutrition 302015 302015 0 0
Obesity

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Participants will be required to attend the sensory laboratories at Deakin University on two separate occasions during which detection threshold (DT) and suprathreshold intensity (ST) for glucose (sweet) and maltodextrin (carbohydrate), hedonic ratings for glucose and maltodextrin solutions, and hedonic ratings for a range of sweet and carbohydrate prototypical foods will be determined. For DT and ST measures, participants will be tasting a total of 16 solution samples (8 glucose samples, 8 maltodextrin samples; 25mL each sample), with concentrations ranging from 0.11-6.31% w/v. For hedonic ratings for glucose and maltodextrin, participants will be tasting a total of 16 solution samples (16 glucose samples, 16 maltodextrin samples; 25mL each sample), with concentrations ranging from 0.11-6.31% w/v. Examples of foods that participants will taste includes fairy floss, honey, kidney beans, rice cakes, white rice, white bread, chocolate sauce, dried apples, raisins, pasta, tomato sauce, and pretzels. They will be served in a 30mL medicine cup. Each participant will test both sweet and carbohydrate solutions/foods. During these sessions, participants will also consume two different iso-caloric preload milkshakes (glucose, maltodextrin). Participants were randomly assigned to the sequence of sweet and complex carbohydrate milkshakes using a web-based program (http://randomizer.org) (i.e., either consuming a sweet milkshake in the first visit or complex carbohydrate milkshake).

Demographic information will be collected, including sex, age, and height and weight measurements. BMI (kg/m2) will be calculated from the height and weight measurements. Participants will also be asked to complete a Food Frequency Questionnaire (FFQ) and a Likes and Dislikes Questionnaire online within 1 week of sensory testing. Psychophysics tasks (DT, ST), as well as hedonic ratings for a range of sweet and carbohydrate solutions will be conducted in computerised, partitioned sensory booths in the Centre for Advanced Sensory Science using Compusense Five Software Version 5.2 (Compusense Inc., Ontario, Canada).

To measure hedonic ratings for a range of sweet and carbohydrate foods, participants will be asked to collect food samples from a counter in the Deakin University’s Teaching Food Laboratory. They will then be asked to taste and rate their liking of the foods on their individual workbenches. Filtered deionised water will be used as an oral rinsing agent. Participants will be instructed to rinse their mouths with filtered deionised water for five seconds before beginning each task and between each sample set. To eliminate any visual or olfactory input, all testing sessions will be conducted under red lighting, and participants will be asked to wear nose clips during testing (except hedonic ratings). All solutions were served at room temperature, with a three-digit code allocated to each sample.

Participants will be asked to abstain from eating and drinking (except room temperature water) for two hour prior to each session. Each session will last about 2 hours, and participants will be given breaks between tasks (around 15 minutes).

The sweet (glucose) and carbohydrate (maltodextrin) milkshakes (per 100g) will consist of: 8.8% glucose/maltodextrin (The Melbourne Food Depot, Melbourne, Australia; Star-Dri 5, Tate & Lyle Ingredients Americas, USA), 63.7% long-life skim milk (99.9% fat free; Devondale Murray Goulburn, Melbourne, Australia), 26.5% light thickened cream (~18% fat; Bulla, Derrimut, Australia), and 1.0% imitation vanilla essence (Queen Fine Foods, Alderley, Australia). All milkshakes will be prepared fresh on the day of testing and stored refrigerated (+/- 3 degree celsius) using plastic food storage containers.

Visit one will include collection of demographic data, DT and ST measurements for glucose and maltodextrin solutions, hedonic ratings for sweet foods, and milkshake ad libitum measurements for either one of the milkshakes.

Visit two will include hedonic ratings for sweet and carbohydrate solutions, hedonic ratings for carbohydrate foods, and milkshake ad libitum measurements for either one of the milkshakes.

There is a one week washout period between both visits.

For clarity, 'sweet' foods denotes sweet tasting foods, whereas 'carbohydrate' foods denotes non-sweet carbohydrate foods (e.g., dietary starches).
Intervention code [1] 297468 0
Behaviour
Comparator / control treatment
No control group (crossover study)

Participants were asked to consume both sweet and carbohydrate milkshakes. Each participant was randomly assigned to the sequence of sweet and complex carbohydrate milkshakes using a web-based program
Control group
Active

Outcomes
Primary outcome [1] 301443 0
Possible associations between sweet taste (glucose DT, ST; more sensitive less sensitive), carbohydrate taste sensitivity (maltodextrin DT, ST; less sensitive or more sensitive), and its association with dietary consumption and ad libitum consumption of carbohydrate milkshake (composite primary outcome). Mean taste thresholds for carbohydrates (glucose, maltodextrin) will be determined. Correlations between mean thresholds with dietary consumption (Food frequency questionnaire) and ad libitum intake of milkshakes will be used to determine if there are any associations between sweet taste and carbohydrate taste thresholds with food dietary consumption (both food frequency questionnaire and milkshake intake).
Timepoint [1] 301443 0
Assessed once participants completed all measures (both visits).
Secondary outcome [1] 332679 0
Possible associations between sweet taste and carbohydrate taste sensitivity (less sensitive or more sensitive), and its association with body mass index. Mean taste thresholds for carbohydrates will be determined. Correlations between mean thresholds with body mass index (anthropometry measurements- height, weight, and waist circumference) will be used to determine if there are any associations between carbohydrate taste thresholds with body mass index.
Timepoint [1] 332679 0
Assessed once participants completed all measures (2 visits)
Secondary outcome [2] 333691 0
Possible associations between sweet taste and carbohydrate taste sensitivity (less sensitive or more sensitive), and its association with hedonic ratings for a range of glucose and maltodextrin solutions, and hedonic ratings for prototypical foods were determined. Mean taste thresholds for carbohydrates (glucose, maltodextrin) will be determined. Correlations between mean thresholds with hedonic ratings (solutions, foods) will be used to determine if there are any associations between sweet taste and carbohydrate taste thresholds with hedonic ratings of solutions and foods.
Timepoint [2] 333691 0
Assessed once participants completed all measures (2 visits)

Eligibility
Key inclusion criteria
over the age of 18 years of age and below the age of 85 years.
Minimum age
18 Years
Maximum age
85 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
smokers, pregnant or lactating, known allergies towards any food used in the study to assess taste thresholds

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)
Cross over study, participants were asked to consume both sweet and carbohydrate milkshakes. Each participant was randomly assigned to the sequence of sweet and complex carbohydrate milkshakes using a web-based program (http://randomizer.org).
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Cross over study, participants were asked to consume both sweet and carbohydrate milkshakes. Each participant was randomly assigned to the sequence of sweet and complex carbohydrate milkshakes using a web-based program (http://randomizer.org).
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s


Intervention assignment
Crossover
Other design features
Phase
Not Applicable
Type of endpoint(s)
Efficacy
Statistical methods / analysis
Information collected from participants will be used to:
1. Participants will be split into quartile groups for analysis (i.e., more 1/4 sensitive, 2/4-3/4 normal sensitive, and 1/4 less sensitive). Therefore, at least 120 participants will be recruited in line with the central limits theorem to approximate a normal population distribution (30 participants for each analysis groups) (Field, 2009). We aim to recruit a total of 150 participants to account for dropouts as well as participants who couldn't participate in the study due to allergies to the foods/refusal to taste the foods used in this study.

2. Determine taste thresholds for carbohydrates (maltodextrin, glucose). Correlations between mean thresholds with BMI, food consumption (dietary pattern), and ad libitum intake of carbohydrate foods will be used to determine if there are associations between carbohydrate taste thresholds with food consumption and BMI.

3. Information concerning participant's food consumption and food behaviour will be used to evaluate differences between subject's thresholds.

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 in Australia
Recruitment state(s)
VIC
Recruitment postcode(s) [1] 15573 0
3125 - Burwood

Funding & Sponsors
Funding source category [1] 295897 0
University
Name [1] 295897 0
Deakin University
Address [1] 295897 0
221 Burwood Highway
3125 Burwood, VIC
Country [1] 295897 0
Australia
Primary sponsor type
University
Name
Deakin University
Address
221 Burwood Highway
3125 Burwood, VIC
Country
Australia
Secondary sponsor category [1] 295030 0
None
Name [1] 295030 0
Address [1] 295030 0
Country [1] 295030 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 297176 0
Deakin University Human Research Ethics Committee
Ethics committee address [1] 297176 0
Deakin University- Burwood Campus
221 Burwood Highway
Burwood, 3125, VIC
Ethics committee country [1] 297176 0
Australia
Date submitted for ethics approval [1] 297176 0
03/01/2012
Approval date [1] 297176 0
01/03/2012
Ethics approval number [1] 297176 0
2012_162

Summary
Brief summary
The aim of this project is to investigate if humans are able to detect small amounts of carbohydrate orally and investigate links with dietary consumption, ad libitum consumption of carbohydrate foods, and weight. Over the past decades, behavioural studies demonstrated that rats are very attracted to starch and that starch is preferred to sucrose at low concentrations, suggesting that rats have different taste receptors for sucrose and starch. Carbohydrates, in the form of sugar and starch, represent a major source of food energy. Except for some fruits, plants contain much more starch than sugar, but it is sugar with its sweet taste that is the most sought after carbohydrate. Compared to sugar, starch is rather bland to the human palate, and has been assumed to be tasteless for other animals as well. However, in the past decades, studies using animal models reported that rats are very attracted to the taste of maltodextrin (starch). The results of these studies suggest that starch and sucrose stimulate different taste qualities, indicating there is an independent taste receptor for polysaccharides.

Recent studies investigating carbohydrate sensing in the human oral cavity through exercise performance have also found that exercise performance significantly improved after participants rinsed their mouth with solutions containing maltodextrin (see review by e-Silva et al., 2014). The results suggest that there may be an independent mechanism and pathway for oral carbohydrate detection, but as yet, there is not method for assessing carbohydrate detection thresholds in humans.

A targeted sample of 150 participants will participate in this project and subjects must be over the age of 18 years. It is also preferred that subjects are non-smokers.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 73242 0
Miss Julia Low
Address 73242 0
Centre for Advanced Sensory Science
Deakin University
221 Burwood Highway,
Burwood, 3125 VIC
Country 73242 0
Australia
Phone 73242 0
+61392517247
Fax 73242 0
Email 73242 0
j.low@deakin.edu.au
Contact person for public queries
Name 73243 0
Miss Julia Low
Address 73243 0
Centre for Advanced Sensory Science
Deakin University
221 Burwood Highway,
Burwood, 3125 VIC
Country 73243 0
Australia
Phone 73243 0
+61392517247
Fax 73243 0
Email 73243 0
j.low@deakin.edu.au
Contact person for scientific queries
Name 73244 0
Miss Julia Low
Address 73244 0
Centre for Advanced Sensory Science
Deakin University
221 Burwood Highway,
Burwood, 3125 VIC
Country 73244 0
Australia
Phone 73244 0
+61392517247
Fax 73244 0
Email 73244 0
j.low@deakin.edu.au

No data has been provided for results reporting
Summary results
Not applicable