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Trial registered on ANZCTR


Registration number
ACTRN12618000255280
Ethics application status
Approved
Date submitted
7/02/2018
Date registered
16/02/2018
Date last updated
30/07/2018
Type of registration
Prospectively registered

Titles & IDs
Public title
Modulating Appetite in Overweight Women
Scientific title
The Effect of a Bitter Plant Extract on Food Intake and Appetite in Overweight and Obese Women
Secondary ID [1] 293979 0
None
Universal Trial Number (UTN)
U1111-1207-9224
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Obesity 306494 0
Condition category
Condition code
Diet and Nutrition 305592 305592 0 0
Obesity

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
The study is to determine the effectiveness of a natural dietary bitter plant extract at suppressing appetite and food intake in overweight females. The three treatment arms comprise an acute intervention of a single delayed release capsule containing either a high (250 mg) or low (100 mg) dose of a super-critical CO2 extract of hops (Humulus lupulus) compared with placebo (vehicle control) provided 1 hour before a standard breakfast (1.5 MJ) provided at 9am. A minimum of a 3 day washout period will then follow where participants revert to their normal diet before entering the next treatment arm of the study.
Intervention code [1] 300254 0
Treatment: Other
Comparator / control treatment
The placebo comprises a delayed release capsule containing the vehicle control (Canola oil, Rosemary extract, Silicon Dioxide).
Control group
Placebo

Outcomes
Primary outcome [1] 304720 0
Energy intake at the ad libitum lunch of ham and cheese sandwiches will be measured by double weighing all components of the meal before and after the meal is completed. Energy intake will be calculated using the nutritional analysis software FoodWorks 7 (Xyris Software, Ausralia).
Timepoint [1] 304720 0
The ad libitum lunch will be provided at 1 pm, 5 hours after administration of the delayed release capsule treatment at 8am.
Primary outcome [2] 304798 0
Macronutrient intake at the ad libitum lunch of ham and cheese sandwiches will be measured by double weighing all components of the meal before and after the meal is completed. Macronutrient intake will be calculated using the nutritional analysis software FoodWorks 7 (Xyris Software, Ausralia).
Timepoint [2] 304798 0
The ad libitum lunch will be provided at 1 pm, 5 hours after administration of the delayed release capsule treatment at 8am.
Secondary outcome [1] 342931 0
Between meal subjective ratings of hunger will be collected using computerised 100 mm visual analogue scales. Participants will mark their responses by placing the cursor on the 100-mm scale according to their subjective feeling to the question “How hungry do you feel?” anchored with “Not hungry at all” to “Never been more hungry”
Timepoint [1] 342931 0
Every 30 minutes for 6 hours post treatment (8:00 am until 2:00 pm)
Secondary outcome [2] 342932 0
Between meal subjective ratings of fullness will be collected using computerised 100 mm visual analogue scales. Participants will mark their responses by placing the cursor on the 100-mm scale according to their subjective feeling to the question “How full do you feel?” anchored with “Not full at all” to “totally full”
Timepoint [2] 342932 0
Every 30 minutes for 6 hours post treatment (8:00 am until 2:00 pm)
Secondary outcome [3] 342933 0
Between meal subjective ratings of satiety will be collected using computerised 100 mm visual analogue scales. Participants will mark their responses by placing the cursor on the 100-mm scale according to their subjective feeling to the question “How satisfied do you feel?” anchored by “completely empty” to “cannot eat another bite”.
Timepoint [3] 342933 0
Every 30 minutes for 6 hours post treatment (8:00 am until 2:00 pm)
Secondary outcome [4] 342934 0
Between meal subjective ratings of the desire to eat will be collected using computerised 100 mm visual analogue scales. Participants will mark their responses by placing the cursor on the 100-mm scale according to their subjective feeling to the question “How strong is your desire to eat?” anchored with “Very weak” to “Very strong
Timepoint [4] 342934 0
Every 30 minutes for 6 hours post treatment (8:00 am until 2:00 pm)
Secondary outcome [5] 343045 0
Between meal subjective ratings of Prospective food consumption will be collected using computerised 100 mm visual analogue scales. Participants will mark their responses by placing the cursor on the 100-mm scale according to their subjective feeling to the question “How much do you think you can eat?” anchored with “Nothing at all” to “A large amount”
Timepoint [5] 343045 0
Every 30 minutes for 6 hours post treatment (8:00 am until 2:00 pm)
Secondary outcome [6] 343046 0
Between meal subjective ratings of thirst will be collected using computerised 100 mm visual analogue scales. Participants will mark their responses by placing the cursor on the 100-mm scale according to their subjective feeling to the question "How thirsty do you feel right now?” anchored by “Not thirsty at all” to “Extremely thirsty”
Timepoint [6] 343046 0
Every 30 minutes for 6 hours post treatment (8:00 am until 2:00 pm)
Secondary outcome [7] 343047 0
Between meal subjective ratings of Nausea will be collected using computerised 100 mm visual analogue scales. Participants will mark their responses by placing the cursor on the 100-mm scale according to their subjective feeling to the question “How nauseas do you feel?" anchored by “Not at all” to “Extremely nauseas”.
Timepoint [7] 343047 0
Every 30 minutes for 6 hours post treatment (8:00 am until 2:00 pm)
Secondary outcome [8] 343048 0
Between meal subjective ratings of tiredness will be collected using computerised 100 mm visual analogue scales. Participants will mark their responses by placing the cursor on the 100-mm scale according to their subjective feeling to the question "How tired do you feel?” anchored by “Not at all” to “Extremely tired”.
Timepoint [8] 343048 0
Every 30 minutes for 6 hours post treatment (8:00 am until 2:00 pm)
Secondary outcome [9] 343049 0
Changes in tiredness will also be assessed using the Karolinska Sleepiness Scale, a measure of situational sleepiness using a nine point scale to measure the subjective level of sleepiness at a particular times of day. Participants indicate which level descriptor best reflects the psycho-physical sate experienced in the last 10 min. The descriptors and values are :
1. Extremely alert
2. Very alert
3. Alert
4. Rather alert
5. Neither alert or sleepy
6. Some signs of sleepiness
7. Sleepy, but no effort to keep awake
8. Sleepy, some effort to keep awake
9. Very sleepy, great effort to keep awake, fighting sleep
Timepoint [9] 343049 0
Every 30 minutes for 6 hours post treatment (8:00 am until 2:00 pm)
Secondary outcome [10] 343053 0
Subjective ratings of meal palatability will be collected using computerised 100 mm visual analogue scales. Participants will mark their responses by placing the cursor on the 100-mm scale according to their subjective feeling for the criteria "pleasantness" anchored by “Good” to “Bad”.
Timepoint [10] 343053 0
Immediately after the standard breakfast (1 hour post treatment) and ad libitum lunch (5 hours post treatment).
Secondary outcome [11] 343054 0
Subjective ratings of meal palatability will be collected using computerised 100 mm visual analogue scales. Participants will mark their responses by placing the cursor on the 100-mm scale according to their subjective feeling for the criteria "visual appeal" anchored by “Good” to “Bad”.
Timepoint [11] 343054 0
Immediately after the standard breakfast (1 hour post treatment) and ad libitum lunch (5 hours post treatment).
Secondary outcome [12] 343055 0
Subjective ratings of meal palatability will be collected using computerised 100 mm visual analogue scales. Participants will mark their responses by placing the cursor on the 100-mm scale according to their subjective feeling for the criteria "smell" anchored by “Good” to “Bad”.
Timepoint [12] 343055 0
Immediately after the standard breakfast (1 hour post treatment) and ad libitum lunch (5 hours post treatment).
Secondary outcome [13] 343056 0
Subjective ratings of meal palatability will be collected using computerised 100 mm visual analogue scales. Participants will mark their responses by placing the cursor on the 100-mm scale according to their subjective feeling for the criteria "taste" anchored by “Good” to “Bad”.
Timepoint [13] 343056 0
Immediately after the standard breakfast (1 hour post treatment) and ad libitum lunch (5 hours post treatment).
Secondary outcome [14] 343057 0
Subjective ratings of meal palatability will be collected using computerised 100 mm visual analogue scales. Participants will mark their responses by placing the cursor on the 100-mm scale according to their subjective feeling for the criteria overall palatability anchored by “Good” to “Bad”.
Timepoint [14] 343057 0
Immediately after the standard breakfast (1 hour post treatment) and ad libitum lunch (5 hours post treatment).
Secondary outcome [15] 343058 0
Subjective ratings of meal palatability will be collected using computerised 100 mm visual analogue scales. Participants will mark their responses by placing the cursor on the 100-mm scale according to their subjective feeling for the criteria "aftertaste" anchored by “Much" to "None”.
Timepoint [15] 343058 0
Immediately after the standard breakfast (1 hour post treatment) and ad libitum lunch (5 hours post treatment).
Secondary outcome [16] 343059 0
The time of day of all bowel movements (stool frequency) will be recorded for 24 h post treatment.
Timepoint [16] 343059 0
Over the 24h post treatment
Secondary outcome [17] 343060 0
Stool consistency will also be reported over 24 h in accordance with the Bristol Stool Scale (Lewis & Heaton 1997)
Timepoint [17] 343060 0
Over the 24h post treatment
Secondary outcome [18] 343061 0
Gastrointestinal discomfort will be assessed using a computerised questionnaire adapted from a validated assessment tool (Bovenschen et al. 2006) with some modification (Yuan et al. 2014). Factors evaluated are abdominal pain, epigastric pain, heartburn, regurgitation, abdominal rumbling, bloating, nausea, vomiting, belching, and flatulence measured on a computerised 100 mm visual analogue scales (VAS) anchored with the terms “none” and “unbearable”.
Timepoint [18] 343061 0
Every 30 minutes for 6 hours post treatment (8:00 am until 2:00 pm)

Eligibility
Key inclusion criteria
• Female
• Aged 18-50 years
• Being overweight or obese as determined by a Body Mass Index greater than or equal to 25 kg/m2 and less than or equal to 35 kg/m2
• A waist-hip ratio of greater than 0.8
• Normal menstrual cycle
• Normal gross gastrointestinal tract anatomy, as ascertained by self-report
• Regular pattern of meal consumption (breakfast, lunch and dinner) as determined by self-report.
• Generally healthy, as ascertained by self-report
Minimum age
18 Years
Maximum age
50 Years
Gender
Females
Can healthy volunteers participate?
No
Key exclusion criteria
• Pregnant, trying to get pregnant or currently breast feeding
• Any reported medical conditions or medications known to affect taste, appetite-related parameters, and gastrointestinal function.
• Participation in an active diet program and/or loss/gain of >10% body weight within the last 6 months
• No extreme food restriction as seen in anorexia nervosa or binge eating plus purging (vomiting/using laxatives) and/or excessive physical activity as seen in bulimia or similar eating disorders that alter body composition in a short space of time.
• Highly restrained eater, as ascertained by a score of >18 on the cognitive restraint scale of the Three Factor Eating Questionnaire.
• Smoker or ex-smoker who quit within the last 6 months
• Acute disease at the time of enrolment (defer sampling until –participant recovers),
• Hypersensitivities or allergies to any foods or ingredients included in the study
• Dislike and/or unwilling to consume items listed as study foods
• Unwilling/unable to comply with study protocol
• Participating in another clinical intervention trial

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 based upon a 3 x 3 Latin square design balanced for order of presentation and carry-over effect
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s
The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Crossover
Other design features
Phase
Not Applicable
Type of endpoint(s)
Efficacy
Statistical methods / analysis
Energy intake at the Ad libitum lunch meal is the primary outcome. The power calculations have used the assumptions of outcome differences of 500kJ based on the reduction in per meal food intake shown in previous 14/NTB/25 clinical trial. From Deloose et al 2017 (Deloose et al. 2017) we estimated the Residual SD as a third of the variation: (58*sqrt(20))/3=86 (0dp) and used Russell Lenth power and sample size calculator for a balanced ANOVA on a cross-over design. Using 3 treatments and a sequence of 6 and a target power of 0.8. SD (Residual) = 86.

Data on demographic and anthropometric characteristics will be summarized using descriptive statistics. VAS data throughout the experiment will be analysed using repeated measures Linear Mixed Model ANOVA with appropriate covariance structure (SAS: PROC MIXED, SAS version 9.4, SAS Institute Inc, Cary, NC, 2013). Time to return to pre-treatment baseline for VAS hunger and fullness will also be analysed using the Friedman nonparametric procedure (SPSS version 16.0, SPSS Inc, Chicago, Il, USA, 2007), i.e. to assess the possibility of breakfasts resulting in ‘suppression of hunger’ and ‘fuller for longer’ across treatments. Energy and macronutrient intake data from the ad lib lunch meal will be analysed using repeated measures Linear Mixed Model. Where the repeated measures Linear Mixed Model ANOVA is significant, Tukey’s post hoc analysis will be used for comparisons between conditions.

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 outside Australia
Country [1] 9560 0
New Zealand
State/province [1] 9560 0
Auckland

Funding & Sponsors
Funding source category [1] 298612 0
Other
Name [1] 298612 0
The New Zealand Institute for Plant & Food Research Limited
Address [1] 298612 0
Plant & Food Research
120 Mt Albert Road,
Sandringham,
Auckland, 1025,
New Zealand
Country [1] 298612 0
New Zealand
Primary sponsor type
Other
Name
The New Zealand Institute for Plant & Food Research Limited
Address
Plant & Food Research
120 Mt Albert Road,
Sandringham,
Auckland, 1025,
New Zealand
Country
New Zealand
Secondary sponsor category [1] 297770 0
None
Name [1] 297770 0
Address [1] 297770 0
Country [1] 297770 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 299571 0
Health and Disability Ethics Committees
Ethics committee address [1] 299571 0
Ministry of Health
133 Molesworth Street
PO Box 5013
Wellington, 6011
Ethics committee country [1] 299571 0
New Zealand
Date submitted for ethics approval [1] 299571 0
23/01/2018
Approval date [1] 299571 0
13/03/2018
Ethics approval number [1] 299571 0
18/NTB/18

Summary
Brief summary
Control of food intake is of primary importance in maintaining good health and is central to the success of interventions designed to manage body weight and to reduce risk factors for metabolic disorder and its consequences, such as obesity, type-2 diabetes, cardiovascular disease and some cancers. We have recently demonstrated that activation of gastrointestinal bitter taste receptors using a highly bitter, non-nutritive, plant extract can suppress energy intake via the release of gut satiety hormones in lean healthy men.
We hypothesise that consumption of this extract will also decrease energy intake at a subsequent ad libitum lunch meal and modify subjective rating of appetite in overweight or obese but otherwise healthy women.
To test this hypothesis 30 overweight or obese women will be recruited into a randomised, double-blind, placebo controlled, cross-over study designed to investigate the acute effect of a single high (250 mg) or low (100 mg) dose of the extract verses a placebo (vehicle control) on energy intake and subjective ratings of appetite, palatability, nausea, tiredness and gastrointestinal side effects.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 80878 0
Dr John Ingram
Address 80878 0
Plant & Food Research
Private Bag 92169, Auckland Mail Centre, Auckland, 1142, New Zealand
Country 80878 0
New Zealand
Phone 80878 0
+64 9 925 7119
Fax 80878 0
+64 9 925 7001
Email 80878 0
john.ingram@plantandfood.co.nz
Contact person for public queries
Name 80879 0
Dr John Ingram
Address 80879 0
Plant & Food Research
Private Bag 92169, Auckland Mail Centre, Auckland, 1142, New Zealand
Country 80879 0
New Zealand
Phone 80879 0
+64 9 925 7119
Fax 80879 0
+64 9 925 7001
Email 80879 0
john.ingram@plantandfood.co.nz
Contact person for scientific queries
Name 80880 0
Dr john ingram
Address 80880 0
Plant & Food Research
Private Bag 92169, Auckland Mail Centre, Auckland, 1142, New Zealand
Country 80880 0
New Zealand
Phone 80880 0
+64 9 925 7119
Fax 80880 0
+64 9 925 7001
Email 80880 0
john.ingram@plantandfood.co.nz

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