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Trial registered on ANZCTR


Registration number
ACTRN12618000638235
Ethics application status
Approved
Date submitted
17/04/2018
Date registered
23/04/2018
Date last updated
2/05/2019
Date data sharing statement initially provided
2/05/2019
Type of registration
Prospectively registered

Titles & IDs
Public title
ICECAP: Intermittent versus Continuous Energy Restriction Compared in an Athlete Population
Scientific title
Effect of Continuous Versus Intermittent Moderate Energy Restriction for Increased Fat Mass Loss and Fat Free Mass Retention in Adult Athletes
Secondary ID [1] 294292 0
Nil
Universal Trial Number (UTN)
Trial acronym
ICECAP
Linked study record

Health condition
Health condition(s) or problem(s) studied:
WEIGHT LOSS 307003 0
Condition category
Condition code
Diet and Nutrition 306096 306096 0 0
Other diet and nutrition disorders
Metabolic and Endocrine 306097 306097 0 0
Normal metabolism and endocrine development and function

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
This study will comprise of 3 phases: [1] Pre-energy restriction phase, [2] Energy restriction phase, and [3] Post-energy restriction phase. The Pre-energy restriction phase consists of training participants how to use a mobile application for self-monitoring energy and macronutrient intake during a diet log over 1 week. The diet log will be followed by a 4-week period of weight maintenance. Weight maintenance energy requirements will be estimated for each participant using a sequential series of prediction equations that take into consideration age, sex, body size and physical activity level, as described previously (1). Participants will be instructed to contact the lead researcher (JP) if weight is gained or lost consecutively for 3 days, in which case they will be provided with an amended diet prescription to maintain weight stability. During the Energy restriction phase all participants will be randomised to continuous or intermittent energy restriction interventions. The continuous intervention consists of 12 weeks on a diet eliciting a weekly weight loss of 0.7% of the participant's Pre-energy restriction body weight in line with previous findings (2). The intermittent intervention consists of 12 weeks of total energy restriction administered as 3 weeks of energy restriction on the diet described above, followed by 1-week of energy balance on a diet at 100% of maintenance energy requirements, for a total of 15 weeks. Both interventions will be administered by the lead researcher (JP). If the participant achieves a weekly weight loss of < 0.5% of their Pre-energy restriction body weight, then the daily energy intake of the prescribed diet will be reduced by 5% to help keep participants at approximately the same rate of weight loss throughout the study, in keeping with a method commonly used by athletes to amend energy intake during weight loss interventions. Adherence to the allocated intervention will be evaluated via weekly review of participant food diaries and partially by success in reaching weekly weight loss targets. In the Post-energy restriction phase participants will complete a 6-month free-living period during which time there will not be any scheduled dietary support from the research team. The macronutrient prescription in energy restriction and energy balance will be based on previous nutritional recommendations for athletes undergoing weight loss interventions (3): protein intake of 2.3 g/kg of body weight, dietary fat intake of 20% of energy intake, with remaining energy intake allocated to carbohydrate to support training demands.

(1) Gerrior S, Juan W, Peter B. An Easy Approach to Calculating Estimated Energy Requirements. . Preventing Chronic Disease. 2006;3(4).
(2) Garthe I, Raastad T, Refsnes PE, Koivisto A, Sundgot-Borgen J. Effect of two different weight-loss rates on body composition and strength and power-related performance in elite athletes. International journal of sport nutrition and exercise metabolism. 2011;21(2):97-104.
(3) Helms ER, Aragon AA, Fitschen PJ. Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. Journal of the International Society of Sports Nutrition. 2014;11:20.
Intervention code [1] 300597 0
Treatment: Other
Intervention code [2] 300598 0
Lifestyle
Comparator / control treatment
Continuous Energy Restriction is the control treatment
Control group
Active

Outcomes
Primary outcome [1] 305128 0
Change in fat mass (in kg)
Assessed using Dual Energy X-ray Absorptiometry (DXA)
Timepoint [1] 305128 0
From 0 weeks to after 12 weeks of moderate energy restriction
Primary outcome [2] 305129 0
Change in fat free mass (in kg)
Assessed using Dual Energy X-ray Absorptiometry (DXA)
Timepoint [2] 305129 0
From 0 weeks to after 12 weeks of moderate energy restriction
Secondary outcome [1] 344272 0
Change in body weight (in kg)
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] 344272 0
From 0 weeks to after 12 weeks of moderate energy restriction
From 0 weeks to 15 weeks
From 0 weeks to 6 months
Secondary outcome [2] 344273 0
Change in fat mass (in kg)
Assessed using Dual Energy X-ray Absorptiometry (DXA)
Timepoint [2] 344273 0
From 0 weeks to 15 weeks
From 0 weeks to 6 months
Secondary outcome [3] 344274 0
Change in fat free mass (in kg)
Assessed using Dual Energy X-ray Absorptiometry (DXA)
Timepoint [3] 344274 0
From 0 weeks to 15 weeks
From 0 weeks to 6 months
Secondary outcome [4] 344275 0
Change in muscle performance (via isokinetic dynamometry)
Timepoint [4] 344275 0
From 0 weeks to after 12 weeks of moderate energy restriction
From 0 weeks to 15 weeks
Secondary outcome [5] 344276 0
Change in subjective drive to eat (by self-report questionnaire)

Participants will have their subjective drive to eat evaluated using a custom self-report questionnaire designed for this study based upon previously-published recommendations on how to measure appetite (1, 2). Participants will be asked to answer questions concerning their current drive to eat, and their overall drive to eat during the past week.

1. Gibbons C, Finlayson G, Dalton M, Caudwell P, Blundell JE. Metabolic Phenotyping Guidelines: studying eating behaviour in humans. J Endocrinol. 2014;222(2):G1-12.
2. Blundell J, de Graaf C, Hulshof T, Jebb S, Livingstone B, Lluch A, et al. Appetite control: methodological aspects of the evaluation of foods. Obes Rev. 2010;11(3):251-70.


Timepoint [5] 344276 0
From 0 weeks to after 12 weeks of moderate energy restriction
From 0 weeks to 15 weeks
Secondary outcome [6] 344277 0
Change in plasma levels of appetite-regulating hormones (leptin, peptide YY and ghrelin)
Timepoint [6] 344277 0
From 0 weeks to after 12 weeks of moderate energy restriction
From 0 weeks to 15 weeks
Secondary outcome [7] 344278 0
Change in mood states (by self-report questionnaire)

Mood states will be evaluated via completion of the Profile of Mood States (POMS-24), which has been applied successfully in athlete populations (1).

1. Rohlfs IC, de Carvalho T, Rotta TM, Krebs RJ. Application of mood states validation instruments in the detection of the overtraining syndrome. Revista Brasileira de Medicina do Esporte. 2004;10(2):111-6.

Timepoint [7] 344278 0
From 0 weeks to after 6 weeks of moderate energy restriction
From 0 weeks to 12 weeks
Secondary outcome [8] 344279 0
Change in diet acceptability (by self-report questionnaire)

We will evaluate athlete perception of their assigned intervention via completion of a custom-made Process Evaluation Questionnaire
Timepoint [8] 344279 0
From 0 weeks to after 6 weeks of moderate energy restriction
From 0 weeks to 12 weeks
Secondary outcome [9] 344280 0
Change in physical activity (by self-report questionnaire and 3-dimensional wrist accelerometer analysis)

Participants will be asked to complete daily training diaries designed specifically for this study to detect potential changes in training load across the trial.
Timepoint [9] 344280 0
From 0 weeks to after 6 weeks of moderate energy restriction
From 0 weeks to 12 weeks
Secondary outcome [10] 344281 0
Change in sleep quality (by self-report questionnaire and 3-dimensional wrist accelerometer analysis)

Sleep will be monitored qualitatively by completion of the Pittsburgh Sleep Quality Index (1), the most frequently cited index for evaluating sleep quality and quantity, and the Epworth Sleepiness Scale (2).

1. Fedson AC, Pack AI, Gislason T. Frequently used sleep questionnaires in epidemiological and genetic research for obstructive sleep apnea: a review. Sleep Med Rev. 2012;16(6):529-37.
2. Johns MW. Reliability and factor analysis of the Epworth Sleepiness Scale. Sleep. 1992;15(4):376-81.
Timepoint [10] 344281 0
From 0 weeks to after 6 weeks of moderate energy restriction
From 0 weeks to 12 weeks
Secondary outcome [11] 344282 0
Change in resting metabolic rate via indirect calorimetry
Timepoint [11] 344282 0
From 0 weeks to after 12 weeks of moderate energy restriction
From 0 weeks to 15 weeks

Eligibility
Key inclusion criteria
Completed greater than or equal to 2 resistance exercise sessions per week for the previous 6 months or more
Willing to comply with a dietary weight loss intervention for ~5 months, involving weight loss for ~3-4 months and weight stability for ~1-2 months
Minimum age
18 Years
Maximum age
No limit
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Current smoker or gave up smoking within the last 6 months
Pregnant or desiring to be pregnant within the next 10 months

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)
To minimise confounding variance, participants will be stratified by sex and sport, using permuted blocks of random sizes. The block sizes will not be disclosed to investigators administering the intervention, to ensure allocation concealment. To avoid bias, randomisation will be undertaken by an investigator who has not had contact with participants before randomisation, and who is not involved in implementation of the dietary interventions. Participants will be assigned with a 1:1 allocation ratio to either the continuous or intermittent energy restriction intervention.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
A computer-generated randomisation process
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s


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

Recruitment
Recruitment status
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)
WA

Funding & Sponsors
Funding source category [1] 298974 0
University
Name [1] 298974 0
University of Western Australia
Address [1] 298974 0
35 Stirling Hwy, Crawley WA 6009
Country [1] 298974 0
Australia
Primary sponsor type
University
Name
University of Western Australia
Address
35 Stirling Hwy, Crawley WA 6009
Country
Australia
Secondary sponsor category [1] 298198 0
None
Name [1] 298198 0
Address [1] 298198 0
Country [1] 298198 0
Other collaborator category [1] 280137 0
Individual
Name [1] 280137 0
Professor Amanda Sainsbury-Salis
Address [1] 280137 0
The Boden Institute of Obesity, Nutrition, Exercise & Eating Disorders, Charles Perkins Centre, John Hopkins Drive, The University of Sydney, NSW, 2006
Country [1] 280137 0
Australia
Other collaborator category [2] 280138 0
Individual
Name [2] 280138 0
Dr Eric Helms
Address [2] 280138 0
Level 2, AUT Millennium, 17 Antares Place, Rosedale, Auckland 0632, New Zealand
Country [2] 280138 0
New Zealand
Other collaborator category [3] 280139 0
Individual
Name [3] 280139 0
Paul Fournier
Address [3] 280139 0
The University of Western Australia (UWA), School of Human Sciences, Crawley Campus, WA 6009
Country [3] 280139 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 299876 0
Human Ethics Office - University of WA
Ethics committee address [1] 299876 0
Human Ethics office
Research Enterprise, University of Western Australia
35 Stirling Highway, Crawley WA 6009
Ethics committee country [1] 299876 0
Australia
Date submitted for ethics approval [1] 299876 0
28/03/2018
Approval date [1] 299876 0
23/05/2018
Ethics approval number [1] 299876 0
RA/4/20/4340

Summary
Brief summary
Athletes commonly reduce body weight or body fat prior to contest seeking various competitive advantages. Intermittent energy restriction is known to effectively reduce body fat in non-athletes, however evidence in athletic populations is lacking. We thus aim to provide an evidence-based intermittent energy restriction protocol for athletes, by investigating this dietary model in a cohort of resistance trained athletes, using a macronutrient profile thought to maximise retention of fat free mass and performance during energy restriction. We will compare changes in fat mass, fat free mass and performance between a continuous and intermittent dieting approach. Measures of body composition, resting energy expenditure, hunger and satiety, blood hormone levels, and muscle strength and endurance will be taken at a number of time points throughout the study.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 81834 0
Mr Jackson Peos
Address 81834 0
University of Western Australia
35 Stirling Highway, Crawley WA 6009
Country 81834 0
Australia
Phone 81834 0
+61 421 712 283
Fax 81834 0
Email 81834 0
jackson.peos@research.uwa.edu.au
Contact person for public queries
Name 81835 0
Mr Jackson Peos
Address 81835 0
University of Western Australia
35 Stirling Highway, Crawley WA 6009
Country 81835 0
Australia
Phone 81835 0
+61 421 712 283
Fax 81835 0
Email 81835 0
jackson.peos@research.uwa.edu.au
Contact person for scientific queries
Name 81836 0
Mr Jackson Peos
Address 81836 0
University of Western Australia
35 Stirling Highway, Crawley WA 6009
Country 81836 0
Australia
Phone 81836 0
+61 421 712 283
Fax 81836 0
Email 81836 0
jackson.peos@research.uwa.edu.au

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
What supporting documents are/will be available?
No other documents available
Summary results
No Results