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Trial registered on ANZCTR


Registration number
ACTRN12610000673044
Ethics application status
Approved
Date submitted
16/08/2010
Date registered
17/08/2010
Date last updated
17/08/2010
Type of registration
Retrospectively registered

Titles & IDs
Public title
Changes in oral sensitivity to oleic acid following dietary modification.
Scientific title
Changes in oral sensitivity (taste thresholds) to oleic acid in lean and overweight/obese humans following consumption of a high-fat (>44%) and low-fat (<20%) diet.
Secondary ID [1] 252470 0
n/a
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Taste sensitivity 257961 0
Condition category
Condition code
Diet and Nutrition 258129 258129 0 0
Obesity

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Consumption of a high-fat (>45%) and low-fat (<20%) diet both over a 4 week period, with a compulsory 2 week wash-out period in between. Specific high-fat foods, including butter, baked goods, dressing, cheese, chocolate and full-fat diary were delivered to all subjects during the high-fat intervention. Fat intakes (in grams per day) were calculated from Energy Requirements based on age, height, weight, gender and Physical Activity Level (PAL) to constitute 45% total energy intake. For the low-fat diet, subjects were advised by a Nutritionist which foods they were not allowed to consumed including all discretionary fats (oils, lard, butter), full-fat dairy, baked goods, high-fat meats (duck, salami) and what foods they should eat when dining out, i.e., tomato based pasta dishes, or lean meats (chicken / fish). To ensure compliance, weekly diet records were collected from all subjects, whom were informed over how to correctly fill in a diet record by a Nutritionist. Foods were delivered to subjects on a weekly basis, and this is when diet records were also collected.
Intervention code [1] 257016 0
Behaviour
Comparator / control treatment
Trial was a crossover trial - so all individuals were their own control
Control group
Active

Outcomes
Primary outcome [1] 258993 0
Changes in taste sensitivity to oleic acid, a common fatty acid in the food supply, via the measurment of taste thresholds
Timepoint [1] 258993 0
At baseline before both intervention periods, and a week 4 of both intervention periods.
Secondary outcome [1] 265195 0
Changes in diet, i.e., a reduction in fat consumption on the low fat diet, and an increase in fat consumption on the high fat diet, in both absolute (g) and relative (% total energy) terms. All food records were entered into FOODWORKS and analysed using the AUSNUT 2007 database for foods, brands and supplements. Changes in dietary intake were measured as changes from baseline (that is before the intervention began).
Timepoint [1] 265195 0
At baseline, before both intervention periods, and during each week of each dietary trial.
Secondary outcome [2] 265196 0
Changes in fat perception, that is the ability to detect differing concentrations of oil (0, 2, 6 and 10%) in a food matrix (custard).
Timepoint [2] 265196 0
At baseline and during week four of both dietary interventions.

Eligibility
Key inclusion criteria
Non-smoker, unrestrained eater (as defined by use of the 3 factor eating questionnaire), healthy (free of ill health complications), not on a specific dietary regime (vegan, low-fat, diabetic ect)
Minimum age
18 Years
Maximum age
80 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Smokers, restrained eaters, individuals with known health complications, i.e., heart diease or diabetes.

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)
Subjects were recruited into the study, and interviewed over the phone to see if they were eligible, i,e., non-smokers, free of diease. Subjects who passsed the phone screening were invited to the Sensory Laboratories at Deakin University, and asked to fill in the 3 factor eating questionnaire - to remove anyone with signs of an eating disorder. Subjects were then allocatted into one of 2 groups. GROUP 1: would receive the high- fat diet followed by the low-fat diet, and GROUP 2: would receive the low-fat diet followed by the high-fat diet. Subjects were allocated by drawing letters either A or B out of an envelope, A would belong to GROUP 1 and B to GROUP 2.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
A predetermined number of letters were drawn up, 15 A and 15 B, and placed in a sealed envelope. Subjects were allocated itno one of the intervention groups dependent upin which letter was drawn.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



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

Recruitment
Recruitment status
Completed
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] 257468 0
Government body
Name [1] 257468 0
Commonwealth Scientific and Industrial Research Organisation
Address [1] 257468 0
671 Sneydes Road,
Werribee, 3030
Victoria
Country [1] 257468 0
Australia
Primary sponsor type
Government body
Name
Food Futures Flagship scholarship
Address
671 Sneydes Road
Werribee 3030
Victoria
Country
Australia
Secondary sponsor category [1] 256695 0
University
Name [1] 256695 0
Deakin University
Address [1] 256695 0
221 Burwood Highway
Burwood 3125
Victoria
Country [1] 256695 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 259494 0
Deakin University Human Research Ethics Comittee
Ethics committee address [1] 259494 0
Research services division,
221 Burwood Highway,
Burwood 3125
Victoria
Ethics committee country [1] 259494 0
Australia
Date submitted for ethics approval [1] 259494 0
05/05/2008
Approval date [1] 259494 0
05/07/2008
Ethics approval number [1] 259494 0

Summary
Brief summary
Previous studies from our laboratories, have reported variation in taste sensitivity to fatty acids (fats) in humans, and that these variations may be asociated with fat intake and the perception of fat in food, that is, the ability to detect fats in food. Based on this evidence, we were interested in looking at environmental influences (i.e., the intake of a high- or low-fat diet, and how it may influence taste sensitivity to fats, given that habituation of the taste system in response to exposure or deprivation of certain nutrients (sodium, monosodium glutamate), has been previously established. Determinants of fatty acid taste sensitivity are of particular interest, given that sensitivity appears to be associated with specific dietary behaviours (i.e., fat intake) which may be associated with obesity. We hypothesized that the taste system would habituate to environmental conditions, and that consumption of a high- or low fat diet would shift sensitivity, i.e., consumption of a high fat diet would decrease taste sensitivity to fatty acids, meaning that greater concentrations would be required for detection, and conversely, a low-fat diet would increase taste sensitivity
Trial website
n/a
Trial related presentations / publications
Stewart et al "Oral sensitivity to fatty acids, food consumption and BMI in human subjects" British Journal of Nutrition, 2010, 104; 145-152.
Public notes

Contacts
Principal investigator
Name 31522 0
Address 31522 0
Country 31522 0
Phone 31522 0
Fax 31522 0
Email 31522 0
Contact person for public queries
Name 14769 0
Dr Russell Keast
Address 14769 0
School of Exercise and Nutritional Sciences
Deakin University
221 Burwood Highway,
Burwood, 3125
Victoria
Country 14769 0
Australia
Phone 14769 0
+613 9224 6944
Fax 14769 0
+613 9244 6017
Email 14769 0
russell.keast@deakin.edu.au
Contact person for scientific queries
Name 5697 0
Dr Russell Keast
Address 5697 0
School of Exercise and Nutritional Sciences
Deakin University
221 Burwood Highway,
Burwood, 3125
Victoria
Country 5697 0
Australia
Phone 5697 0
+613 9224 6944
Fax 5697 0
+613 9244 6017
Email 5697 0
russell.keast@deakin.edu.au

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary