Please note that the copy function is not enabled for this field.
If you wish to
modify
existing outcomes, please copy and paste the current outcome text into the Update field.
LOGIN
CREATE ACCOUNT
LOGIN
CREATE ACCOUNT
MY TRIALS
REGISTER TRIAL
FAQs
HINTS AND TIPS
DEFINITIONS
Trial Review
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 endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this
information for consumers
Download to PDF
Trial registered on ANZCTR
Registration number
ACTRN12614000141640
Ethics application status
Approved
Date submitted
16/01/2014
Date registered
5/02/2014
Date last updated
3/04/2018
Type of registration
Prospectively registered
Titles & IDs
Public title
Investigation of the Impact of Degree of Weight Loss on Physiological Adaptations to Weight Loss
Query!
Scientific title
An interventional study investigating if starting BMI or degree of weight loss affect physiological adaptations to weight loss using a VLED (very low energy diet)
Query!
Secondary ID [1]
283922
0
nil
Query!
Universal Trial Number (UTN)
U1111-1146-9120
Query!
Trial acronym
nil
Query!
Linked study record
Query!
Health condition
Health condition(s) or problem(s) studied:
Obesity
290921
0
Query!
Condition category
Condition code
Diet and Nutrition
291277
291277
0
0
Query!
Obesity
Query!
Intervention/exposure
Study type
Interventional
Query!
Description of intervention(s) / exposure
Very Low Energy Diet (VLED) (OptiFast) for 12 weeks. All participants will be placed on OptiFast for a duration of 12 weeks. The OPTIFAST program is a total food
replacement for the overweight. It is intended for use as part of the management of the moderately to severely overweight persons. The OPTIFAST program has been clinically developed and scientifically formulated to totally replace normal food intake. Weight loss is comparable to that achieved by total fasting whilst minimising the complications of severe ketosis and muscle loss. The OPTIFAST formulation includes high quality protein, sufficient quantities of protein (for nitrogen sparing
and to preserve lean body mass), carbohydrates, fatty acids, and follows the Recommended Dietary Intake (RDI) for vitamins, minerals and trace elements. Fortnightly measurements of urinary ketones will be taken to gauge adherence to diet.
Query!
Intervention code [1]
288608
0
Treatment: Other
Query!
Comparator / control treatment
Overweight adults compared to obese adults
Query!
Control group
Uncontrolled
Query!
Outcomes
Primary outcome [1]
291278
0
Degree of reduction in body weight required to bring about compensatory mechanisms (assessed using weight measurements via calibrated scales, measurements of gut hormones (amylin, PYY, GLP-1, leptin ,ghrelin, GIP,PP and INSL5)glucose, insulin and free fatty acids via serum assays)
Query!
Assessment method [1]
291278
0
Query!
Timepoint [1]
291278
0
12 weeks
Query!
Primary outcome [2]
291317
0
To investigate if body weight is equally regulated across a range of BMIs (assessed using weight measurements via calibrated scales, measurements of gut hormones (amylin, PYY, GLP-1, leptin ,ghrelin, GIP,PP and INSL5)glucose, insulin and free fatty acids via serum assays)
Query!
Assessment method [2]
291317
0
Query!
Timepoint [2]
291317
0
week 64
Query!
Secondary outcome [1]
306411
0
Degree of weight regain from week 13-64 (assessed via weight measurements using calibrated scales)
Query!
Assessment method [1]
306411
0
Query!
Timepoint [1]
306411
0
week 64
Query!
Secondary outcome [2]
306501
0
Change from baseline to week 12; and week 13-64 in gut hormone measurements, fasting glucose measurement, fasting insulin measurement and appetite (as measured by visual analogue scale)(assessed using weight measurements via calibrated scales, measurements of gut hormones (amylin, PYY, GLP-1, leptin ,ghrelin, GIP,PP and INSL5)glucose, insulin and free fatty acids via serum assays)
Query!
Assessment method [2]
306501
0
Query!
Timepoint [2]
306501
0
week 64
Query!
Eligibility
Key inclusion criteria
*Written informed consent obtained
*Age 18 – 65 years
*BMI 25-50kg/m2
*Stable body weight
*In good health
Query!
Minimum age
18
Years
Query!
Query!
Maximum age
65
Years
Query!
Query!
Sex
Both males and females
Query!
Can healthy volunteers participate?
No
Query!
Key exclusion criteria
*Body builders
*Significant illness
*History of recent weight loss
*Past history of bariatric surgery
*Use of weight affecting pharmacotherapy
*Current smokers
*History of unstable thyroid disorder
Query!
Study design
Purpose of the study
Treatment
Query!
Allocation to intervention
Non-randomised trial
Query!
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Query!
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Query!
Masking / blinding
Open (masking not used)
Query!
Who is / are masked / blinded?
Query!
Query!
Query!
Query!
Intervention assignment
Parallel
Query!
Other design features
Query!
Phase
Not Applicable
Query!
Type of endpoint/s
Efficacy
Query!
Statistical methods / analysis
The power calculations for this study were based on the expected change in ghrelin levels after weight loss. We propose that average percentage change in ghrelin between the 5% weight loss measurement and 15% weight loss measurement is at least in the vicinity of 0%. To account for natural variation not associated with weight loss we suppose that the percentage change between these two time periods is SD = 25. We assume that equivalence proven if mean percentage change is within +/- 10%. Assuming SD=25%, 70 subjects are required to achieve a power of 90%. To account for attrition, it is proposed that a total recruitment of 100 subjects as an appropriate sample size to study based on an expected attrition rate of 30%.
Additional to the exploration of equivalence between groups, for comparisons between two time points, changes in measurements will be analysed using either a paired t-test or the non-parametric Wilcoxon signed-rank test as appropriate. Changes in hormones and VAS will be analysed using linear mixed effect (lme) models to factor in fixed effects week (i.e. week of visit), time (time of measurement within week), , subject as the random effect and will also allow for adjustment and analysis with respect to covariates. Additionally, changes in hormones will also be modelled using various baseline anthropometric predictors and change in these measures after phase I.
Query!
Recruitment
Recruitment status
Active, not recruiting
Query!
Date of first participant enrolment
Anticipated
Query!
Actual
5/02/2014
Query!
Date of last participant enrolment
Anticipated
31/12/2015
Query!
Actual
5/06/2015
Query!
Date of last data collection
Anticipated
31/12/2018
Query!
Actual
Query!
Sample size
Target
100
Query!
Accrual to date
Query!
Final
104
Query!
Recruitment in Australia
Recruitment state(s)
VIC
Query!
Recruitment hospital [1]
1973
0
Austin Health - Heidelberg Repatriation Hospital - Heidelberg West
Query!
Recruitment postcode(s) [1]
7702
0
3081 - Heidelberg Heights
Query!
Funding & Sponsors
Funding source category [1]
288561
0
University
Query!
Name [1]
288561
0
University of Melbourne
Query!
Address [1]
288561
0
1—100 Grattan Street,
Parkville, Victoria, 3010
Query!
Country [1]
288561
0
Australia
Query!
Primary sponsor type
University
Query!
Name
University of Melbourne
Query!
Address
1—100 Grattan Street,
Parkville, Victoria, 3010
Query!
Country
Australia
Query!
Secondary sponsor category [1]
287275
0
None
Query!
Name [1]
287275
0
Query!
Address [1]
287275
0
Query!
Country [1]
287275
0
Query!
Ethics approval
Ethics application status
Approved
Query!
Ethics committee name [1]
290423
0
Austin Health HREC
Query!
Ethics committee address [1]
290423
0
145 Studley Rd
Heidelberg VIC 3084
Query!
Ethics committee country [1]
290423
0
Australia
Query!
Date submitted for ethics approval [1]
290423
0
Query!
Approval date [1]
290423
0
14/11/2013
Query!
Ethics approval number [1]
290423
0
HREC/13/Austin/154
Query!
Summary
Brief summary
There is evidence that public health measures aimed at reducing the burden of obesity have not been effective. Whilst there are several possible reasons for this, including a multitude of competing messages, the overabundance of energy dense food and the near absence of obligatory physical activity, it is likely that the more important reason is the fact that weight appears to be physiologically regulated and defended. This means that using public health measures to combat obesity is not likely to work for obese subjects. What is not yet known is if subjects who are overweight (as opposed to obese), defend weight loss, nor is it known if modest (~5%) weight loss is defended. If overweight or modest weight losses are not defended, it would allow the targeting of public health messages towards the overweight and to focus on modest weight loss in the obese.
This study aims to investigate if overweight people defend weight loss as vigorously as obese people, and to determine at what degree of weight loss these physiological changes begin. Overweight and obese people will be recruited and placed on a VLED (very low energy diet) for a period of 12 weeks, aiming to decrease body weight by 15%. Measurements in body weight and a number of biomarkers will be taken at proscribed intervals. All participants will be followed up for a period of two years, to observe weight regain (if any). Gut hormone and other biomarker changes over the trial will be compared between the overweight cohort and the obese cohort, to determine any differences. For both cohorts, changes in gut hormones and other biomarkers will be compared at 5%, 10% and 15% baseline body weight lost, to determine when physiological defences increase.
Query!
Trial website
Query!
Trial related presentations / publications
Edwards KL, Kalfas S, Prendergast LA, Proietto J. Investigation of the impact of degree of weight loss on physiological adaptations to weight loss.
(Poster presentation at Australian and New Zealand Obesity Society Annual Scientific Meeting 2014)
Kira Edwards, Luke Prendergast, Stefanie Kalfas, Priya Sumithran, Joseph Proietto. Effect of weight loss on plasma INSL5 in humans.
(Poster presentation at the European Congress on Obesity 2017)
Kira Edwards, Luke Prendergast, Stefanie Kalfas, Priya Sumithran, Joseph Proietto. The Relationship between Degree of Weight Loss and Changes in Gut Hormones that Control Hunger and Satiety.
(Oral Presentation at the Australian and New Zealand Obesity Society Annual Scientific Meeting 2017; Finalist, ANZOS Early Career Researcher Awards)
Query!
Public notes
Query!
Contacts
Principal investigator
Name
45630
0
Prof Joseph Proietto
Query!
Address
45630
0
University of Melbourne, Department of Medicine
L2 Boronia Centre, Heidelberg Repatriation Hospital
300 Waterdale Rd
Heidelberg Heights VIC 3081
Query!
Country
45630
0
Australia
Query!
Phone
45630
0
+61 3 9496 2250
Query!
Fax
45630
0
+61 3 9496 2672
Query!
Email
45630
0
[email protected]
Query!
Contact person for public queries
Name
45631
0
Ms Kira Edwards
Query!
Address
45631
0
University of Melbourne, Department of Medicine
L2 Boronia Centre, Heidelberg Repatriation Hospital
300 Waterdale Rd
Heidelberg Heights VIC 3081
Query!
Country
45631
0
Australia
Query!
Phone
45631
0
+61 3 9496 2124
Query!
Fax
45631
0
+61 3 9496 2672
Query!
Email
45631
0
[email protected]
Query!
Contact person for scientific queries
Name
45632
0
Prof Joseph Proietto
Query!
Address
45632
0
University of Melbourne, Department of Medicine
L2 Boronia Centre, Heidelberg Repatriation Hospital
300 Waterdale Rd
Heidelberg Heights VIC 3081
Query!
Country
45632
0
Australia
Query!
Phone
45632
0
+61 3 9496 2250
Query!
Fax
45632
0
+61 3 9496 2672
Query!
Email
45632
0
[email protected]
Query!
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
Source
Title
Year of Publication
DOI
Embase
Impact of starting BMI and degree of weight loss on changes in appetite-regulating hormones during diet-induced weight loss.
2022
https://dx.doi.org/10.1002/oby.23404
N.B. These documents automatically identified may not have been verified by the study sponsor.
Download to PDF