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Trial registered on ANZCTR


Registration number
ACTRN12611000057987
Ethics application status
Not yet submitted
Date submitted
11/01/2011
Date registered
17/01/2011
Date last updated
17/01/2011
Type of registration
Prospectively registered

Titles & IDs
Public title
Genetic and environmental influences on taste receptors in the prevention of obesity
Scientific title
Genetic and environmental influences on taste receptors in the prevention of obesity amongst individuals who are hyper (more) and hypo (less) sensitive to prototypical taste stimuli as measured via the evaluation of taste function and taste receptor gene expression, prior to, and following four weeks consumption of a standardised (DASH) diet.
Secondary ID [1] 253386 0
Nil
Universal Trial Number (UTN)
U1111-1119-0014
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Obesity 260939 0
Condition category
Condition code
Diet and Nutrition 259071 259071 0 0
Obesity

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
During this study, subjects will be evaluated for their taste sensitivity to a number of prototypical taste stimuli including sucrose (sweet taste), citric acid (sour taste), sodium chloride (salty taste), caffeine (bitter taste), oleic acid (fatty acid taste) and monosodium glutamate (umami taste). Individuals who are hyper- or hypo- sensitive to any of these taste stimuli, as defined by a score greater than, or less than 2 standard deviations from the mean, will be asked to participate in the study, which will involve consumption of a standardised diet, the Dietary Approaches to Stop Hypertension (DASH) diet. Whilst this diet was developed to reduce sodium intake, it is accepted as a suitable diet for general health, due to the high levels of fruits and vegetables, as well as whole grains that comprise the diet, and limitations on sugars and fats. The DASH diet will be customized to each participant. For this, all participants will receive recipe cards for cooking DASH style meals and information on how much of each specific food or food group (vegetables, fruits etc) they will be required to consume. In general, the DASH diet recommends the following 1) 7-8 serves of whole grains (whole wheat breads, pasta, cereals etc), 2) 4-5 serves of vegetables (where 1 serve is equal to 1 cup of raw vegetables, or 1/2 cup cooked vegetables), 3) 4-5 serves of fruit (where 1 serve is equal to 1 medium fruit, 1/4 cup dried fruit or 1/2 cup canned fruit), 4) 2-3 serves of low-fat or fat free dairy (where 1 serve is equal to 200 g yoghurt or 200 mls milk), 5) 2-3 serves of oils and fats (where 1 serve is equal to 1 teaspoon of unsaturated oil, low-fat salad dressing, or mayonnaise) per day. To account for differences in body size and energy needs, all diets will be customized for each participant. Taste sensitivity as well as taste receptor gene expression will be measured prior to and following the diet intervention, which will run for four weeks. For this, all participants will complete 4 X 30 minute taste tests, two prior to the intervention, and two during week four of the intervention, as well as 2 x 30 minute testing sessions where tongue tissue will be collected, once prior to, and the other following the intervention. The DASH diet will be consumed by all participants for 4 weeks.
Intervention code [1] 257833 0
Treatment: Other
Comparator / control treatment
no control - all subjects will consume the diet
Control group
Uncontrolled

Outcomes
Primary outcome [1] 259929 0
The primary outcome in this study will be taste sensitivity, which will be measured via determining the detection threshold, which is the lowest amount of tastant required for it to be detected, for the following tastants sucrose (sweet taste), citric acid (sour taste), sodium chloride (salty taste), caffeine (bitter taste), oleic acid (fatty acid taste) and monosodium glutamate (umami taste).
Timepoint [1] 259929 0
Taste thresholds will be established prior to the intervention and during week four of the dietary intervention
Primary outcome [2] 259930 0
The second primary outcome will be taste receptor gene expression, which will be measured via collecting micrograms of tongue tissue, by gently scraping the tongue with a cell scrapper or cell brush. Tongue tissue will be combined with commercially available gene probes, which are used to measure the expression of taste receptor genes
Timepoint [2] 259930 0
Taste receptor gene expression will be established prior to the intervention and during week four of the dietary intervention
Secondary outcome [1] 268834 0
Dietary intake changes as a result of the intervention will be captured by use of 24 hour food recalls.
Timepoint [1] 268834 0
Repeat 24 hour food recalls will be collected prior to initiating the diet, to measure recent food intake. During the intervention, one 24 hour food recall will be collected per week, to measure dietary changes whilst consuming the DASH diet

Eligibility
Key inclusion criteria
- Adults over the age of 18 years
- Adults living in the Sydney metropolitan area
- Adults with good written and spoken English
-Adults who can attend testing sesions between 9:00am - 5:00pm Monday to Friday
Minimum age
18 Years
Maximum age
55 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
-Adults with medical conditions known to influence weight
-Adults who are currently, or have been within the past 3 months on a diet, or consuming a special diet
-Adults whose weight has fluctuated by more than 3 kilograms in the past 3 months
-Adulst older than 55 years
-Adults who are restrained eaters
-Adults who are allergic to, or do not wish to consume dairy based products
-Adults with impaired taste, or those consuming medication known to affect taste
-Smokers

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)
All subjects will participate in the dietary intervention
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Who is / are masked / blinded?



Intervention assignment
Other design features
Phase
Type of endpoint(s)
Statistical methods / analysis

Recruitment
Recruitment status
Not yet 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)

Funding & Sponsors
Funding source category [1] 258303 0
Government body
Name [1] 258303 0
Commonwealth Scientific and Industrial Research Organisation (CSIRO)
Address [1] 258303 0
Riverside Corportae Park
11 julius Avenue
North Ryde
2113
NSW
Country [1] 258303 0
Australia
Primary sponsor type
Individual
Name
Dr Conor Delahunty
Address
CSIRO Food and Nutritional Sciences
Riverside Corportae Park
11 julius Avenue
North Ryde
2113
NSW
Country
Australia
Secondary sponsor category [1] 257467 0
Government body
Name [1] 257467 0
Commonwealth Scientific and Industrial Research Organisation (CSIRO)
Address [1] 257467 0
CSIRO Food and Nutritional Sciences
Riverside Corportae Park
11 julius Avenue
North Ryde
2113
NSW
Country [1] 257467 0
Australia

Ethics approval
Ethics application status
Not yet submitted
Ethics committee name [1] 260287 0
CSIRO Food and Nutritional Sciences Human Research Ethics Commitee
Ethics committee address [1] 260287 0
CSIRO Food and Nutritional Sciences
Kintor Road
Adelaide
5000
South Australia
Ethics committee country [1] 260287 0
Australia
Date submitted for ethics approval [1] 260287 0
31/01/2011
Approval date [1] 260287 0
Ethics approval number [1] 260287 0

Summary
Brief summary
This study will evaluate the influence of diet on taste sensitivity and taste receptor gene expression in healthy subjects
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 32080 0
Address 32080 0
Country 32080 0
Phone 32080 0
Fax 32080 0
Email 32080 0
Contact person for public queries
Name 15327 0
Ms Jessica Stewart
Address 15327 0
CSIRO Food and Nutritional Sciences
Riverside Corporate Park
11 Julius Avenue
North Ryde
2113
Country 15327 0
Australia
Phone 15327 0
+ 61 2 9490 8363
Fax 15327 0
Email 15327 0
jessica.stewart@csiro.au
Contact person for scientific queries
Name 6255 0
Ms Jessica Stewart
Address 6255 0
CSIRO Food and Nutritional Sciences
Riverside Corporate Park
11 Julius Avenue
North Ryde
2113
Country 6255 0
Australia
Phone 6255 0
+ 61 2 9490 8363
Fax 6255 0
Email 6255 0
jessica.stewart@csiro.au

No information has been provided regarding IPD availability
Summary results
No Results