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Trial registered on ANZCTR


Registration number
ACTRN12612000881831
Ethics application status
Not yet submitted
Date submitted
16/08/2012
Date registered
20/08/2012
Date last updated
20/08/2012
Type of registration
Prospectively registered

Titles & IDs
Public title
The effect of prolonged dietary exposure and the association between taste receptor expression, fatty acid taste sensitivity and satiety in healthy weight participants
Scientific title
Investigating the effect of a crossover high and low fat dietary intervention on fatty acid taste receptor expression, fatty acid taste sensitivity and satiety in healthy weight participants
Secondary ID [1] 281039 0
Nil
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Overweight and obesity 287096 0
Condition category
Condition code
Diet and Nutrition 287423 287423 0 0
Obesity

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Subjects will participate in a crossover dietary intervention, involving consumption of both a high and low fat diet for a period of 10 weeks each, with a two week wash out period. The high fat diet will consist of 40% fat while participants on the low fat diet will be asked to consume <20% fat. To account for differences in energy needs, all diets will be customised to each participant.

For the high fat diet, participants will be provided with a number of high fat foods (i.e. full cream milk, cooking oil, butter, cheese, chocolate bars, nuts, avocado, muffins etc) on a weekly basis and will be supplied with an information sheet detailing which foods to consume and how many portions of each (i.e. 250g toasted muesli and 1 chocolate bar).

Participants on the low fat diet will be instructed to limit their dietary fat consumption to <20% total energy. Participants will be provided with nutritional advice and an information package to assist with compliance of the diet. Participants will be asked to swap high fat foods for low fat alternatives (e.g. full-fat dairy for low fat dairy and high fat salad dressing for low fat salad dressing) and discontinue the use of oil, butter and other cooking fats. Participants will also be asked not to consume other sources of fats including nuts, avocado, take away food (pizza, burgers, hot chips), processed meat or meat with visible fat or snack foods such as chocolate or potato chips. The diet will also supplemented with additional foods such as low fat, portion controlled meals which the participant will be allowed to consume for either lunch or dinner. A low fat recipe booklet will also be provided to assist with food preparation.

To assess dietary adherence, weekly 24-hour food records will be completed. A number of measures will also be taken prior to, during and following the intervention to evaluate the effect of dietary fat intake on fatty acid taste sensitivity, taste receptor expression and corresponding satiety responses.

In one session, fatty acid taste sensitivity will be measured using milk samples with added oleic acid (and control samples with no added oleic acid) using a three-alternate forced choice sensory procedure. Putative fatty acid taste receptor expression (GPR120, GPR40 and CD36) will be measured by collecting a microgram quantity of taste cells in saliva samples. The procedure will involve participants running their teeth along the front of the tongue (fungiform papillae) with sufficient pressure and will be asked to expectorate into a tube until approximately 1mL of saliva is collected. RNA level will be measured using real time PCR techniques. Participants will also perform a fat ranking task using custard samples varying in fat percentage (0, 2, 6 and 10%) to assess fat perception and rate liking of various high and low fat foods. Height, weight, hip and waist circumference will be measured.

Within 7 days, participants will be provided with, and asked to consume a standardised breakfast (approximately 1200kJ consisting of cereal, milk, yoghurt, fruit and tea/coffee) on the morning of testing. Participants will rate appetite, prospective food consumption and hunger perceptions on a 100mm visual analogue scale before and after consumption of the breakfast. Three hours later, participants will return to the sensory laboratory where food consumption will be measured. Participants will be presented with a buffet style lunch, with foods presented in excess (10,000kJ) and asked to eat until comfortably full. The amount of food consumed will be calculated by weighing the meal prior to, and following consumption (in grams). Energy intake will also be calculated. Participants will again rate appetite perceptions using the satiety questionnaire.
Intervention code [1] 285424 0
Lifestyle
Comparator / control treatment
In this study, participants will act as their own control. Following exposure to a high and low fat diet, changes between baseline and week 10 measures will be identified.
Control group
Active

Outcomes
Primary outcome [1] 287686 0
Fatty acid taste sensitivity as determined by sensory methodology (3-alternate forced choice procedure) using milk samples with and without oleic acid.Taste sensitivity will be measured by determining the detection threshold, which is the lowest amount of tastant required for it to be detected.
Timepoint [1] 287686 0
Baseline, midway point (week 5) and following diet (week 10).
Primary outcome [2] 287687 0
Fatty acid taste receptor expression as measured via collection in saliva samples. Tongue tissue will be combined with commercially available gene probes, which are used to measure the expression of taste receptor genes.
Timepoint [2] 287687 0
Baseline, midway point (week 5) and following diet (week 10)
Primary outcome [3] 287688 0
Perceived satiety as assessed via food consumption at a buffet style meal and scores on a 100mm visual analogue scale (VAS). Participants will be provided with a buffet style lunch and asked to eat until comfortably full. The amount of food (in grams) and energy (kJ) consumed will be calculated. Participants will be asked to rate common appetite perceptions including fullness, hunger and prospective food consumption before and after consumption of the meal.
Timepoint [3] 287688 0
Baseline, midway point (week 5) and following diet (week 10).
Secondary outcome [1] 298625 0
Nil
Timepoint [1] 298625 0
Nil

Eligibility
Key inclusion criteria
- Adults >18 years of age
- Healthy weight individuals (BMI <25)
- Adults living in Melbourne
- Adults with good written and spoken English
- Adults who are able to attend Deakin University, Burwood and complete testing sessions between the hours of 9-6pm Monday-Friday
Minimum age
18 Years
Maximum age
65 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
- Overweight/obese subjects (BMI >25)
- Restrained eaters
- Those who have food allergies or intolerances, or who do not wish to consume certain food products
- Smokers
- Consumption of a vegetarian diet
- Adults whose weight has fluctuated more than 3kg in the past 3 months
- Adults who are taking medication known to affect weight or taste sensitivity

Study design
Purpose of the study
Prevention
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation is not concealed
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation like coin tossing or dice rolling
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Crossover
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] 285765 0
University
Name [1] 285765 0
Deakin University, School of Exercsie and Nutritional Sciences, Centre for Physical Activity and Nutritional Sciences
Address [1] 285765 0
221 Burwood Highway
Burwood
VIC 3125
Country [1] 285765 0
Australia
Primary sponsor type
University
Name
Deakin University, School of Exercsie and Nutritional Sciences, Centre for Physical Activity and Nutritional Sciences
Address
221 Burwood Highway
Burwood
VIC 3125
Country
Australia
Secondary sponsor category [1] 284593 0
None
Name [1] 284593 0
Address [1] 284593 0
Country [1] 284593 0

Ethics approval
Ethics application status
Not yet submitted
Ethics committee name [1] 287847 0
Ethics committee address [1] 287847 0
Ethics committee country [1] 287847 0
Date submitted for ethics approval [1] 287847 0
05/09/2012
Approval date [1] 287847 0
Ethics approval number [1] 287847 0

Summary
Brief summary
This study will investigate the effect of prolonged dietary fat intake on fatty acid taste receptor expression (GPR120, GPR40 and CD36), fatty acid taste sensitivity and corresponding satiety responses.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 34542 0
Address 34542 0
Country 34542 0
Phone 34542 0
Fax 34542 0
Email 34542 0
Contact person for public queries
Name 17789 0
Rivkeh Haryono
Address 17789 0
School of Exercise and Nutrition Sciences
Deakin University
221 Burwood Highway
Burwood
Victoria 3125
Country 17789 0
Australia
Phone 17789 0
+61 03 9251 7286
Fax 17789 0
Email 17789 0
rharyono@deakin.edu.au
Contact person for scientific queries
Name 8717 0
A/Prof Russell Keast
Address 8717 0
School of Exercise and Nutrition Sciences
Deakin University
221 Burwood Highway
Burwood
Victoria 3125
Country 8717 0
Australia
Phone 8717 0
+61 03 9244 6944
Fax 8717 0
Email 8717 0
russell.keast@deakin.edu.au

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