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Trial registered on ANZCTR


Registration number
ACTRN12615000116527
Ethics application status
Approved
Date submitted
12/01/2015
Date registered
10/02/2015
Date last updated
10/01/2019
Type of registration
Prospectively registered

Titles & IDs
Public title
MATADOR 2: Minimising Adaptive Thermogenesis And Deactivating Obesity Rebound 2
Scientific title
Effect of Intermittent Versus Continuous Energy Restriction on Body Weight, Resting Metabolic Rate and Neuroendocrine Function in Obese Women.
Secondary ID [1] 285956 0
Nil
Universal Trial Number (UTN)
U1111-1165-9578
Trial acronym
MATADOR 2
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Obesity 293885 0
Condition category
Condition code
Metabolic and Endocrine 294188 294188 0 0
Normal metabolism and endocrine development and function
Diet and Nutrition 294189 294189 0 0
Obesity

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
The study is secondary to the previously registered MATADOR study (ACTRN12611001017910) which was undertaken in males. The MATADOR 2 study will be undertaken in females with a comparitive cohort of males.

The study will comprise 3 phases: [1] Baseline energy balance, [2] Energy restriction intervention, and [3] Post-intervention energy balance. As we have previously shown that provision of food maximises dietary compliance in the free-living situation (1,2,4), food will be home-delivered weekly to participants in all phases of this study. The aim of PHASE 1 is to determine the baseline values of various parameters of the famine reaction before energy restriction and weight loss. During the 4 weeks of PHASE 1, weight stability will be achieved as we have previously published (1-4), by determining maintenance energy requirements from dietary history and resting metabolic rate (RMR), and then providing participants with a weight maintenance diet. In PHASE 2, participants will be randomised to continuous or intermittent energy restriction interventions. The continuous intervention consists of 16 weeks on a diet at 67% of maintenance energy requirements. The intermittent intervention consists of 16 weeks of total energy restriction administered as 2 weeks of energy restriction on a diet at 67% of maintenance energy requirements followed by 2 weeks of energy balance on a diet at 100% of maintenance energy requirements, for a total of 30 weeks. The interventions are designed to elicit a 10% body weight loss. To account for weight lost, the energy restriction will be indexed to body weight and RMR after every 4 weeks of energy restriction, thereby keeping theoretical relative energy deficit consistent across the 12-week period. In PHASE 3, participants will be placed on an energy balance diet referenced to their reduced-weight state for 4 weeks to examine the time course of recovery of metabolic and neuroendocrine markers. The macronutrient distribution in both energy restriction and energy balance diets will be maintained within the range of 25–30% of energy as fat, 15-20% as protein, and 50–60% as carbohydrate. As we have previously shown that provision of food maximises dietary compliance in the free-living situation (1,2,4), food will be home-delivered weekly to participants in this study.

1. Weinsier RL, Hunter GR, Desmond RA, Byrne NM, Zuckerman PA, Darnell BE. Free-living activity energy expenditure in women successful and unsuccessful at maintaining a normal body weight. Am J Clin Nutr. 2002; 75(3):499-504.
2. Byrne NM, Hills AP, Wood RE. Does body composition, relative energy deficit or adaptive thermogenesis explain differences between predicted and actual weight loss in obese adults? Obesity Reviews. 2010;11(Suppl.1):35-36.
3. Byrne NM, Weinsier RL, Hunter GR, et al. Influence of distribution of lean body mass on resting metabolic rate after weight loss and weight regain: comparison of responses in white and black women. Am J Clin Nutr. 2003;77(6):1368-73.
4. Wood RE, Byrne NM, Groves AM, Hills AP, King NK. Achieving energy balance in apparently sedentary obese males. Obesity Reviews. 2010;11(Suppl.1):219
Intervention code [1] 290928 0
Treatment: Other
Intervention code [2] 290929 0
Lifestyle
Comparator / control treatment
Continuous energy restriction is the control treatment (females).

A representative sample of males will also be recruited for comparative data to the previous MATADOR study that was undertaken at QUT. This is important for gender response comparisons between the MATADOR 1 study which was undertaken in males at QUT and the MATADOR 2 study in females that will be undertaken at Bond University. Therefore, to ensure the independent variable/confounder (study location) is having no effect, a representative sample of males will be recruited at Bond University for comparitive purposes to the QUT cohort. It is anticipated there will be no difference in response between the 10 recruited males who will all undertake the intermittant protocol in comparision to the intermitant male cohort in MATADOR 1.
Control group
Active

Outcomes
Primary outcome [1] 293974 0
Body weight will be measured using digital weighing scales. Digital weighing scales are to be used to monitor body weight of participants at home in times between laboratory visits. These scales will be calibrated regularly, and weight will also be measured at the standard laboratory sessions.
Timepoint [1] 293974 0
Daily - 4 weeks energy balance (pre-intervention)
Daily - 12 weeks (continuous) or 22 weeks (intermittent) energy restriction
Daily - 4 weeks energy balance (post-intervention)
12 and 24 week follow up
Primary outcome [2] 293975 0
Resting metabolic rate via indirect calorimetry
Timepoint [2] 293975 0
Week 1,2 and 4 - energy balance (pre-intervention)
Week 2, 4, 6, 8, 10 and 12 - energy restriction
Week 2, 4 - energy balance (post-intervention)
Primary outcome [3] 293976 0
Neuroendocrine status: Overnight fasted blood samples will be collected and concentrations of the following analytes in serum or plasma will be determined: free T3, Free T4, reverse T3, TSH, ACTH, cortisol, testosterone, sex hormone binding globulin, IGF-1, and leptin
Timepoint [3] 293976 0
Week 1 and 4 - energy balance (pre-intervention)
Week 2, 4, 6, 8, 10 and 12 - energy restriction
Week 2, 4 - energy balance (post-intervention)
12 and 24 week follow up
Secondary outcome [1] 312264 0
Body composition (Fat Mass and Fat-free Mass) will be assessed using the gold-standard 4-compartment model using air displacement plethysmography (via BodPod), deuterium dilution and Dual Energy X-ray Absorptiometry (DXA) at 5 time points: in energy balance immediately prior to (Phase 1), at start of, mid way and after the weight loss intervention (Phase 2) and after the 4-wk period of energy balance (Phase 3). In addition, BodPod measurements will be taken at week 1, 2 and 4 energy balance (pre-intervention), weeks 2, 4, 6, 8, 10 and 12 of energy restriction, and weeks 2 and 4 of energy balance (post-intervention).
Timepoint [1] 312264 0
Week 1,2 and 4 - energy balance (pre-intervention)
Week 2, 4, 6, 8, 10 and 12 - energy restriction
Week 2, 4 - energy balance (post-intervention)
Secondary outcome [2] 312265 0
Fasting substrate oxidation via indriect calorimetry
Timepoint [2] 312265 0
Week 1,2 and 4 - energy balance (pre-intervention)
Week 2, 4, 6, 8, 10 and 12 - energy restriction
Week 2, 4 - energy balance (post-intervention)
Secondary outcome [3] 312266 0
Markers of metabolic health (fasting serum glucose, insulin, triglycerides, cholesterol)
Timepoint [3] 312266 0
Week 1 and 4 - energy balance (pre-intervention)
Week 2, 4, 6, 8, 10 and 12 - energy restriction
Week 2, 4 - energy balance (post-intervention)
Secondary outcome [4] 312267 0
Satiety via visual analogue scales and ad libitum test meal.
Timepoint [4] 312267 0
Week 1 and 4 energy balance (pre-intervention)
Week 6 and 12 - energy restriction
Week 4 (post-intervention)

Eligibility
Key inclusion criteria
Sedentary (< 60 mins physical activity per week)
Class I or II obese (30-40kg.m-2)
Waist circumference >102 cm
Euthyroid, non-diabetic, ambulatory, and weight stable for at least 6 months (+/-2kg)
Minimum age
25 Years
Maximum age
55 Years
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Diabetic or fasting blood glucose > 6.0 mmol/L (from medical screening)
Major surgery that will affect gut function/metabolic rate
Arthritis/musculoskeletal problems that would preclude full participation in all testing/affect activities of daily living
Heart condition
Sleep apnoea
Thyroid condition
Current smoker or gave up smoking within the last 6 months
Any medications known to affect metabolic rate or neuroendocrine function
Non-ambulatory
Currently on a “diet” or actively losing weight

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)
Participants will be stratified according to BMI (30-34.9, 35-40) and age (25-38.9, 39-55) and then randomly allocated into either the intermittent energy restriction or continuous energy restriction groups.
Allocation is not concealed.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Pemuted block randomisation. Where intermittent energy restriction = 1 and continuous energy restriction = 2.
Where BMI (30-34.9) = A, BMI (35-40) = B, Age (25-38.9) = C, Age (39-55) = D. Each participant will therefore fall into one of four cell options: AC, AD, BC or BD. Each cell will have pair allocations of random sequence 1 or 2.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint(s)
Efficacy
Statistical methods / analysis

Recruitment
Recruitment status
Not yet recruiting
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)
QLD

Funding & Sponsors
Funding source category [1] 290537 0
Government body
Name [1] 290537 0
National Health and Medical Research Council
Address [1] 290537 0
Level 1
16 Marcus Clarke Street
Canberra ACT 2601
Country [1] 290537 0
Australia
Primary sponsor type
Individual
Name
Professor Nuala Byrne
Address
c/o Bond Institute of Health & Sport
2 Promethean Way, Robina.
4226, Queensland.
Country
Australia
Secondary sponsor category [1] 289229 0
University
Name [1] 289229 0
Bond University
Address [1] 289229 0
University Drive
Varsity Lakes
QLD, 4227
Country [1] 289229 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 292183 0
Bond University Human Research Ethics Committee (BUHREC)
Ethics committee address [1] 292183 0
c/o Bond University
University Drive,
Varsity Lakes, 4227. QLD.
Ethics committee country [1] 292183 0
Australia
Date submitted for ethics approval [1] 292183 0
Approval date [1] 292183 0
08/01/2015
Ethics approval number [1] 292183 0

Summary
Brief summary
There are more than 7 million overweight or obese adults in Australia and on average only about 5% of this population
achieve permanent weight reduction of any significance to their health. Many questions remain regarding the best way to achieve long-term weight loss, and how a person’s metabolic rate is affected both in the short- and long-term during dieting.
The overall aim of this project is to design more effective and sustainable weight loss strategies for overweight and obese adults. This study, funded by the National Health and Medical Research Council (NHMRC), aims to compare changes in weight and health using two different dieting approaches in female participants with a small comparitive male cohort; one in which the energy intake (kilojoule value) changes every two weeks, and the other where the energy intake changes every four weeks. Throughout the intensive phase of the study, participants are provided with a healthy, balanced, energy-regulated diet delivered to their home. Measures of body composition, metabolic rate and energy expenditure, hunger and satiety, blood hormone levels, body fuel usage, and metabolic health will be taken at a number of time points throughout the study
Trial website
www.matador2.com
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 53966 0
Prof Nuala Byrne
Address 53966 0
c/o Bond Institute of Health & Sport
2 Promethean Way,
Robina. 4226. Queensland.
Country 53966 0
Australia
Phone 53966 0
(07) 5595 2279
Fax 53966 0
Email 53966 0
nbyrne@bond.edu.au
Contact person for public queries
Name 53967 0
Prof Nuala Byrne
Address 53967 0
c/o Bond Institute of Health & Sport
2 Promethean Way,
Robina. 4226. Queensland.
Country 53967 0
Australia
Phone 53967 0
(07) 5595 2279
Fax 53967 0
Email 53967 0
nbyrne@bond.edu.au
Contact person for scientific queries
Name 53968 0
Prof Nuala Byrne
Address 53968 0
c/o Bond Institute of Health & Sport
2 Promethean Way,
Robina. 4226. Queensland.
Country 53968 0
Australia
Phone 53968 0
(07) 5595 2279
Fax 53968 0
Email 53968 0
nbyrne@bond.edu.au

No information has been provided regarding IPD availability
Summary results
No Results