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Trial registered on ANZCTR


Registration number
ACTRN12614000434695
Ethics application status
Approved
Date submitted
24/03/2014
Date registered
29/04/2014
Date last updated
28/05/2014
Type of registration
Prospectively registered

Titles & IDs
Public title
The effect of bitter phytochemicals on food intake
Scientific title
The effect of an orally consumed bitter phytochemical extract (or placebo control) on food intake at a subsequent meal in healthy normal weight men.
Secondary ID [1] 284300 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
obesity 291446 0
Poor appetite control 291498 0
Condition category
Condition code
Diet and Nutrition 291819 291819 0 0
Obesity

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
The study is a randomised, double-bind cross-over treatment in 20 healthy male participants and will involve the delivery of commonly consumed dietary bitter compounds (oral capsules) or placebo control, to assess its effects on appetite and energy intake. Capsules will be given to the participants at the time of the treatment to ensure they are taken.

The study will be of 3 days duration, during which time 3 treatment arms each of 1 day duration will be completed in randomized order with at least a 7-day washout between treatments. The 3 treatment arms consist of 2 bitter phytochemical treatments and 1 placebo control.

All treatments comprise of 2 capsules, one acid stable one taken 60 minutes before the lunch and one non-acid stable one taken 30 minutes before the lunch. For the 3 arms participants will receive either:
1. 2 placebo capsules (Placebo) at 30 and 60 minutes prior (acid stable capsule) to lunch.
2. A placebo at 60 minutes prior to lunch in the acid stable capsule and a 500mg plant extract (See non-public information for extract details) in a normal cellulose capsule at 30min prior to lunch (Stomach targeted)
3. A 500mg plant extract (See non-public information for extract details) in an acid stable capsule 60 minutes before lunch and a placebo in a normal cellulose capsule 30 minutes before lunch.

The reason for the 2 different treatment locations is because animal studies have shown that the effect gastric exposure may differ from that of duodenal exposure.

Treatments are suspended in food grade canola oil as a carrier to facilitate dispersion.
Intervention code [1] 289022 0
Treatment: Other
Intervention code [2] 289225 0
Prevention
Comparator / control treatment
Placebo capsule containing only the canola oil carrier.
Control group
Placebo

Outcomes
Primary outcome [1] 291737 0
Food Intake

The ad libitum lunch and snack meals will be served within individual meal booths, and meals will consist of a pasta and sauce meal (lunch) or sandwiches (snack), where each item is served in excess. Participants will be advised that they can eat as much or as little as they choose and to eat until they are ‘comfortably full’. They will be required to remain within the booth for a period of 30 minutes. When they have finished eating they will raised an ‘I am full’ sign.

Lunch and snack items will be weighed on 2 occasions both before and after each of the ad libitum meals. Energy (kJ), fat, CHO and protein intake will be calculated using the dietary software program Foodworks.
Timepoint [1] 291737 0
30 mins and 1h post intervention for the lunch. Then 2:30 and 3h post intervention for the snack.
Secondary outcome [1] 307373 0
Visual analouge scales (VAS) for appetite related measures

VAS – Hunger, Fullness, Satisfaction, Thoughts of Food, Nausea

VAS will be used following the methodology of Flint et al (Flint, Raben et al. 2000).
The following questions will be used: “How hungry do you feel? / How full do you feel? / How satisfied do you feel? / How much do you think you can eat now / How nauseas do you feel?”

They will be achored on the left with the following statements:
“I am not hungry at all / I am not full at all/ I am completely empty / nothing at all / not nauseas at all”

And on the right with“I am as hungry as I have ever been / I am totally full / I cannot eat another bite / a large amount /very nauseas”

Subjects will mark their responses by placing a vertical line across the 100-mm scale according to their subjective feelings.
Timepoint [1] 307373 0
Ongoing throughout the intervention days.

830h - 150 mins: VAS
900h -120 mins: VAS
0930h: -90 mins: VAS
1000h: -60 mins: VAS
1030h: -30 mins: VAS
1100h: 0 mins: VAS (immediately before duodenal capsule)
1115h: +15min VAS
1130h: +30min VAS (immediately before gastric capsule)
1130h: +30min: Gastric capsule delivered
1145h +45 mins VAS
1200h: +60 mins VAS followed by ad libitum pasta lunch
1230h: +90 mins VAS
1245h: +105 mins VAS
1300h: +120 mins VAS
1315h: +135 mins VAS
1330h: +150 mins VAS
1400h: +180 mins VAS
followed by ad libitum snack
1430h: +210 mins VAS
1500h: +240 mins VAS
1530h: +270 mins VAS
1600h: +300 mins VAS

Eligibility
Key inclusion criteria
Male
Aged 18-55 years
Normal stomach, small intestine and large bowel
Generally healthy
Minimum age
18 Years
Maximum age
55 Years
Sex
Males
Can healthy volunteers participate?
Yes
Key exclusion criteria
Overweight as defined by BMI >25kg/m2

Any medical conditions or medications known to affect appetite -related parameters, including depression

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)
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
A power analysis was performed to provide estimates of variance components using data from a previous test meal experiment performed at the UoA Human Nutrition Unit which also investigated the effect of a test breakfast on satiety in a group of men. Calculations were done on both the primary end point of Ad libitum energy intake at the outcome lunch meal, as well as the secondary endpoint of Hunger & Fulllness VAS scores In the current studies it is anticipated that 20 participants will be required to complete the 3 treatment days, based on the assumptions shown below:

Ad libitum energy intake at the outcome lunch meal:
Energy intake at the ad lib lunch meal is the primary outcome. The power calculations have used the assumptions of outcome differences of 500kJ, equivalent to a change of 5 percent in an individual consuming a typical daily intake of 10MJ/day (=10,000kJ/day). In order to inform as to the within-person standard deviation, numbers corresponding to the smallest (686kJ) and largest (990kJ) standard deviation from the previous trial were used.
Paired data (cross-over) – continuous outcome (EI)
Anticipated standardised effect, Delta = [anticipated difference in outcome500kJ]/[sd of difference of outcome variable measured on two occasions estimated from previous studies]
In order to detect an outcome difference of 5% (500kJ) as significant at P<0.05
(i) Delta = 500/686 = 0.73 80%=17 subjects; 90%=22 subjects
(ii) Delta = 500/990 = 0.51 80%=33 subjects; 90%=42 subjects
Machin, D. et al. Sample Size Tables for Clinical Studies, 3rd Edition, 2008.

The model based upon an estimated error variance taken from the previous study could be larger (or smaller) than previously observed & hence the actual probability of detecting the effect is uncertain. Using the 80% confidence interval (worst case scenario) the number of subjects required is estimated to fall between 17-33 subjects. Based on these calculations, 20 participants will be recruited. Given the potential for participants to withdraw from the study, recruiting 20 people will allow for 80% power even after 3 withdrawals.






Hunger & Fullness assessed by Visual Analogue Score (VAS):
The modelling showed that for a sample size of 20 subjects completing a 3 treatment cross-over design, the power to detect an effect size of 10mm difference from baseline (10%, based on 100mm VAS) in VAS ratings was 0.732. The same repeat measures design was found to have a
power of 0.875 to detect an effect of 12.5mm (12.5%), and 0.951 to detect a larger 15mm (15%) change from baseline as significant. The model, based upon an estimated error variance taken from the previous satiety experiment, cannot allow for the fact that the error in the proposed study could be larger (or smaller) than previously observed and hence the actual probability of detecting the effect is uncertain. Using the upper 90% confidence interval (worst case scenario) the power to detect a 12.5% effect and 15% effect, respectively, fell to 0.83 and 0.88 which may still be considered acceptable. A similar, although not identical, study design was also assessed by Flint et al. (Flint, Raben et al. 2000) who concluded that 20 subjects would be sufficient to detect a difference of 10mm on fasting and 5mm on postprandial ratings, at power 0.8. Our data provide a simlar estimate.


Recruitment
Recruitment status
Active, not recruiting
Date of first participant enrolment
Anticipated
30/04/2014
Actual
30/04/2014
Date of last participant enrolment
Anticipated
15/05/2014
Actual
15/05/2014
Date of last data collection
Anticipated
Actual
Sample size
Target
20
Accrual to date
Final
Recruitment outside Australia
Country [1] 5912 0
New Zealand
State/province [1] 5912 0
Auckland

Funding & Sponsors
Funding source category [1] 288932 0
Government body
Name [1] 288932 0
Ministry of Business, Innovation and Employment (MBIE)
Country [1] 288932 0
New Zealand
Primary sponsor type
Government body
Name
Plant and Food Research
Address
120 Mt Albert Road
Sandringham (1025)
Auckland
New Zealand
Country
New Zealand
Secondary sponsor category [1] 287622 0
None
Name [1] 287622 0
Address [1] 287622 0
Country [1] 287622 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 290757 0
Northern B Health and Disability Ethics Committee
Ethics committee address [1] 290757 0
Health and Disability Ethics Committees
Ministry of Health
C/- MEDSAFE, Level 6, Deloitte House
10 Brandon Street
PO Box 5013
Wellington
6011
Ethics committee country [1] 290757 0
New Zealand
Date submitted for ethics approval [1] 290757 0
27/02/2014
Approval date [1] 290757 0
07/03/2014
Ethics approval number [1] 290757 0
14/NTB/25

Summary
Brief summary
The number of individuals who are overweight or obese is increasing dramatically both globally and within New Zealand. One of the major causes of weight gain is poor appetite control, where individuals overeat (eat more than is required to maintain their current weight) either because they do not generate physiological signals of ‘fullness’ and ‘stop eating’, or because the pleasure associated with eating overrides these signals.
We believe that delivering bitter plant compounds to the gut may regulate appetite and potentially be a possible way to suppress appetite and help people lose weight. This study will give a non-toxic bitter plant extract to people then measure if it affects how much food they eat and how full they feel
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 47102 0
Dr Edward Walker
Address 47102 0
Plant and Food Research
120 Mt Albert Road
Sandringham (1025)
Auckland
Country 47102 0
New Zealand
Phone 47102 0
+64 9 9257050
Fax 47102 0
Email 47102 0
[email protected]
Contact person for public queries
Name 47103 0
Dr Edward Walker
Address 47103 0
Plant and Food Research
120 Mt Albert Road
Sandringham (1025)
Auckland
Country 47103 0
New Zealand
Phone 47103 0
+64 9 9257050
Fax 47103 0
Email 47103 0
[email protected]
Contact person for scientific queries
Name 47104 0
Dr Edward Walker
Address 47104 0
Plant and Food Research
120 Mt Albert Road
Sandringham (1025)
Auckland
Country 47104 0
New Zealand
Phone 47104 0
+64 9 9257050
Fax 47104 0
Email 47104 0
[email protected]

No information has been provided regarding IPD availability


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
SourceTitleYear of PublicationDOI
EmbaseAn extract of hops (Humulus lupulus L.) modulates gut peptide hormone secretion and reduces energy intake in healthy-weight men: A randomized, crossover clinical trial.2022https://dx.doi.org/10.1093/ajcn/nqab418
N.B. These documents automatically identified may not have been verified by the study sponsor.