Working… Menu

Genetics of Bitter and Fat Taste

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 evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT04038281
Recruitment Status : Not yet recruiting
First Posted : July 30, 2019
Last Update Posted : July 30, 2019
Oxford Brookes University
Information provided by (Responsible Party):
Kim Wright, St Mary's University College

Brief Summary:
Obesity is an increasing problem for adults in the UK. Diets high in fat and sugar are the major contributors to weight gain. Individual differences in taste perception are a crucial factor in determining the investigator's choice of foods and an individual's sensitivity to the either bitter or fat taste compounds has been linked to a preference for different foods including sweet and high fat foods. Previous research has not comprehensively explored the effect of both fat and bitter taste sensitivity on dietary intake and obesity status. Therefore, the aim of this study is to explore the associations between genetics, fat and bitter taste sensitivity, food preference, dietary intake and obesity measures in the adult UK population.

Condition or disease Intervention/treatment
Genetics Taste, Altered Diet Habit Obesity Other: Sensory tests

Detailed Description:

Demographic data Participants will complete a questionnaire asking about their demographics provided in Appendix. The answers to these questions will be used to control for potential confounding effects in statistical analysis.

Genetic Analysis Saliva samples (2 ml) will be collected for DNA analyses (Genefix, Isohelix, Kent, UK) and stored in the fridge at 4 °C in M201 lab at St Mary's University. DNA extraction will be carried out through use of a PSP® SalivaGene 17 DNA Kit 1011 following the standard manufacturer protocol. DNA quantification and quality control will be assessed with spectroscopy. Following this, genotyping will be carried out using prepared TaqMan® SNP genotyping assays for genes coding for bitter and fat taste receptors and a StepOnePlus thermocycler. All samples will be analysed in duplicate in accordance with the manufacturer's protocol. All genetic analyses will be carried out at St Mary's University, Twickenham.

Anthropometrics Height (m), weight (kg) and waist circumference (cm) will be recorded by the researcher team. BMI will be calculated using the equation: weight (kg)/ height (m2) ± standard deviation and waist circumference and distribution will be compared to the UK standards.

Fat and bitter taste sensitivity The Oral Fatty Acid Threshold Assessment and Ascending Forced Choice Triangle Procedure will be used to determine each participant's oleic acid (C18:1) detection threshold (fat taste sensitivity). Briefly, each participant will be presented with three cups containing 30 ml vehicles in a random arrangement, two controls and the third containing oleic acid (0.02, 0.06, 1, 1.4, 2, 2.8, 3.8, 5, 6.4, 8, 9.8, 12, 20 mM). Participants will have to identify the oleic acid solution by tasting but not ingesting the solutions. A participant will be required to choose the oleic acid solution correctly three times at the same concentration to define their threshold. If participant is incorrect at any point, further three cups will be presented, one containing the higher concentration. There will be thirteen concentrations in total. The bitter taste compound used to classify participants into bitter taste hypo-, normal- and hypertasters will be PTC. Participants will place a strip on the tongue and use the general Labeled Magnitude Scale (gLMS) to report the intensity of the taste compound.

Food preference Food preference will be measured by asking participants to taste food usually perceived as bitter (dark chocolate and broccoli) as well as food that are defined as sweet (milk chocolate and carrots).To minimise variability, the vegetables will be presented raw. Overall preference will be tested using a nine-point Likert scale. Each participants will rinse their mouth with water between each food and a minimum of one minute will be left between each test. Eating behaviour will be determined by use of the validated Adult Eating Behaviour Questionnaire. Fat preference will be determined by a UK adaption of the validated Fat Preference Questionnaire.

Dietary Intake The validated EPIC Norfolk Food Frequency Questionnaire (FFQ) will be used to measure dietary intake over the previous year.

Layout table for study information
Study Type : Observational
Estimated Enrollment : 100 participants
Observational Model: Other
Time Perspective: Cross-Sectional
Official Title: The Effects of Genetic Variation in the Bitter and Fat Taste Receptor Genes on Taste Perception, Dietary Behaviour and Obesity Status
Estimated Study Start Date : August 15, 2019
Estimated Primary Completion Date : October 1, 2019
Estimated Study Completion Date : November 1, 2019

Resource links provided by the National Library of Medicine

Intervention Details:
  • Other: Sensory tests
    Fat, bitter taste sensitivity and food preference measurement

Primary Outcome Measures :
  1. Obesity [ Time Frame: 1 day observation ]

Secondary Outcome Measures :
  1. Energy intake [ Time Frame: 1 year dietary intake ]
    Energy intake in kcal obtained with FFQ

  2. Fat intake [ Time Frame: 1 year dietary intake ]
    Fat intake in grams obtained with FFQ

  3. Sugar intake [ Time Frame: 1 year dietary intake ]
    Sugar intake in grams obtained with FFQ

Biospecimen Retention:   Samples With DNA
2 ml saliva sample

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Layout table for eligibility information
Ages Eligible for Study:   18 Years to 65 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Probability Sample
Study Population
Healthy Caucasian males and females aged 18-65 years

Inclusion Criteria:

  • healthy adults aged 18-65 years

Exclusion Criteria:

  • pregnancy
  • breastfeeding
  • smoking
  • reported any past or present food allergy or lactose intolerance
  • under any medication that might affect taste perception
  • known illnesses such as cold, ear infection, sinus infection, or flu
  • any reported chronic diseases such as (diabetes, CVD, stroke, epilepsy, asthma, cancer)
  • any thyroid problems
  • individuals that are currently following a diet or weight loss programme

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT04038281

Layout table for location information
United Kingdom
St Mary's University
London, United Kingdom, TW14SX
Sponsors and Collaborators
St Mary's University College
Oxford Brookes University

Layout table for additonal information
Responsible Party: Kim Wright, Research Administrator, St Mary's University College Identifier: NCT04038281     History of Changes
Other Study ID Numbers: SMEC_2018-19_048
First Posted: July 30, 2019    Key Record Dates
Last Update Posted: July 30, 2019
Last Verified: July 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

Layout table for additional information
Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Additional relevant MeSH terms:
Layout table for MeSH terms
Nutrition Disorders
Taste Disorders
Sensation Disorders
Nervous System Diseases
Body Weight
Signs and Symptoms
Neurologic Manifestations