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Trial registered on ANZCTR


Trial ID
ACTRN12617000613303
Ethics application status
Approved
Date submitted
21/04/2017
Date registered
28/04/2017
Date last updated
28/04/2017
Type of registration
Retrospectively registered

Titles & IDs
Public title
Performance, body composition and wellbeing outcomes in New Zealand multisporters following a ketogenic diet.
Scientific title
Performance, body composition and wellbeing outcomes in New Zealand multisporters following a ketogenic diet.
Secondary ID [1] 291750 0
Nil
Universal Trial Number (UTN)
U1111-1195-8316
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
General wellbeing 302970 0
Condition category
Condition code
Diet and Nutrition 302438 302438 0 0
Other diet and nutrition disorders

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
This was a case study design of five recreational multisport athletes (four females, one male), with no control control. Athletes were regularly involved in high-level competitive multisport for at least five years undertook a non-calorie-controlled ketogenic diet (<50g carbohydrate; 1.5g protein / kg body weight; remaining calories from fat) for 10 weeks. All participants were non-smokers, healthy and injury-free as per a health screening questionnaire and not consuming a low carbohydrate diet (defined as carbohydrates less than 45% of total energy intake).

Prior to the start of the intervention, participants underwent a series of tests and a full consultation for dietary instruction and planning as follows:

Performance tests: Participants reported to the lab in the morning in a fasted state and underwent a performance test on three occasions: i. one week prior to the intervention (familiarisation), ii. immediately prior to the intervention (baseline), and iii. immediately post the intervention (post). The performance test was an incremental cycle test using an electromagnetically controlled cycle ergometer to determine VO2peak and gas exchange thresholds (GET) in a temperature-controlled laboratory (21 degrees Celcius, 65 % rH). The test commenced at 30 W and increased by 30 W every 3 minutes until volitional exhaustion. The tests were administered be an experienced exercise physiologist.

Body composition measures:
Body weight and skinfolds were measured by an ISAK level one accredited anthropometrist, prior to and at the conclusion of the intervention, at the same time of the day. A sum of 8-site skinfold ISAK protocol was applied: triceps, biceps, subscapular, iliac crest, supraspinale, abdominal, front thigh and medial calf.

Diet:
An initial consultation was conducted with each participant by the primary researcher/Registered Dietitian directly after the performance test. Participants were provided with a daily macronutrient prescription of <50g total carbohydrate, 1.5 g.kg protein and ad libitum fat. A detailed explanation of the practical application of the ketogenic dietary principles along with appropriate tracking and monitoring procedures was provided. Participants were provided with a sample diet and were advised to add variations provided they adhered to the carbohydrate and protein macronutrient thresholds provided. The were instructed to track their diet using a dietary analysis programme Easy Diet Diary (Xyris Software (Australia) Pty Ltd). Diets were monitored weekly by the primary researcher, and participants were contacted and offered additional support if they deviated. The primary researcher maintained regular contact with all participants throughout the 10-week study duration.

Interviews and focus group. A 20-30 minute individual interview was conducted on the phone at 5 weeks and a 60-minute focus group was conducted in person once the intervention had concluded.

Intervention code [1] 297864 0
Treatment: Other
Intervention code [2] 297877 0
Lifestyle
Comparator / control treatment
No control group
Control group
Uncontrolled

Outcomes
Primary outcome [1] 301847 0
VO2 max. Assessed via a metabolic cart using an incremental cycle test using an electromagnetically controlled cycle ergometer (Ergoselect 100, Ergoline, Bitz, Germany) in a temperature-controlled laboratory.
Timepoint [1] 301847 0
10 weeks
Primary outcome [2] 301887 0
Peak power assessed via an incremental cycle test using an electromagnetically controlled cycle ergometer (Ergoselect 100, Ergoline, Bitz, Germany) in a temperature-controlled laboratory.
Timepoint [2] 301887 0
10 weeks
Primary outcome [3] 301888 0
Time to exhaustion assessed via an incremental cycle test using an electromagnetically controlled cycle ergometer (Ergoselect 100, Ergoline, Bitz, Germany) in a temperature-controlled laboratory.
Timepoint [3] 301888 0
10 weeks
Secondary outcome [1] 334018 0
Body composition i.e. weight and ISAK sum of 8 skinfolds: triceps, biceps, subscapular, iliac crest, supraspinale, abdominal, front thigh and medial calf
Timepoint [1] 334018 0
10 weeks
Secondary outcome [2] 334019 0
General wellbeing via an individual interview and a focus group. Athletes were asked open ended questions about their experiences of the diet overall.
Timepoint [2] 334019 0
5 weeks (interviews)
10 weeks (focus group)

Eligibility
Key inclusion criteria
- Multisport athletes for at least five years, undertaking more than 6 hours a week training and regularly competing in events (recreational or elite).
- Non-smokers, healthy and injury-free as per a health screening questionnaire
- Not consuming a low carbohydrate diet (defined as carbohydrates less than 45% of total energy intake) as per a health screening questionnaire.
Minimum age
18 Years
Maximum age
60 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
- diagnosed with any medical condition
- pregnancy / breastfeeding individual
- non-athlete

Study design
Purpose of the study
Treatment
Allocation to intervention
Non-randomised 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)
N/A
Masking / blinding
Who is / are masked / blinded?



Intervention assignment
Other design features
Phase
Not Applicable
Type of endpoint(s)
Efficacy
Statistical methods / analysis
Data was analysed using mean change scores, with Cohen’s effect sizes and associated confidence limits applied to quantify magnitude of change. A student’s t-test was applied to determine the statistical meaning of the change. All statistics were generated and applied using Microsoft Excel 2016. Level of significance was determined at p<0.01

Interviews and the focus group were recorded, transcribed, and data was analysed using thematic analysis.

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
Current
Final
Recruitment outside Australia
Country [1] 8834 0
New Zealand
State/province [1] 8834 0
Auckland

Funding & Sponsors
Funding source category [1] 296245 0
University
Name [1] 296245 0
Auckland University of Technology
Address [1] 296245 0
AUT - School of Sport & Recreation
Private Bag 92006,
Northcote
Auckland
1020
Country [1] 296245 0
New Zealand
Primary sponsor type
University
Name
Auckland University of Technology
Address
AUT - School of Sport & Recreation
Private Bag 92006,
Northcote
Auckland
1020
Country
New Zealand
Secondary sponsor category [1] 295162 0
None
Name [1] 295162 0
N/A
Address [1] 295162 0
N/A
Country [1] 295162 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 297485 0
AUTEC (AUT Ethics Committee)
Ethics committee address [1] 297485 0
AUT
WU Building, 55 Wellesley St East, City Campus, Auckland City, Auckland, 1010
Ethics committee country [1] 297485 0
New Zealand
Date submitted for ethics approval [1] 297485 0
02/11/2015
Approval date [1] 297485 0
19/11/2015
Ethics approval number [1] 297485 0
15/415

Summary
Brief summary
The efficacy of ketogenic diets on enhanced performance in endurance athletes is equivocal. The purpose of this work was to assess the effects of a 10-week ketogenic diet intervention on the sport performance, body composition and perceived wellbeing of five well-trained multisport athletes.
Trial website
Trial related presentations / publications
None
Public notes
This was a retrospective ethics application. The reason this was is to obtain approval for some work we conducted in our sports science laboratory at AUT-Millenium in 2014, which we decided to write up and submit to a journal for peer-review publication. This work was undertaken with five of our existing colleagues, who are multisport athletes, At the time that this work was conducted, it was not envisaged as a research project that required ethics as we were not intended on publishing the work, and it was a normal part of what we did in our lab. Despite this fact, it was conducted under research-rigorous conditions, as our work of this nature usually is, even under usual clinic protocols. We decided retrospectively that the work is worthy of publication and therefore we applied for ethics, and it was approved.

Contacts
Principal investigator
Name 74190 0
Dr Caryn Zinn
Address 74190 0
Auckland University of Technology
Private Bag 92006
Northcote
Auckland
1020
Country 74190 0
New Zealand
Phone 74190 0
+64 09 921 9999 ext 7842
Fax 74190 0
Email 74190 0
caryn.zinn@aut.ac.nz
Contact person for public queries
Name 74191 0
Dr Caryn Zinn
Address 74191 0
Auckland University of Technology
Private Bag 92006
Northcote
Auckland
1020
Country 74191 0
New Zealand
Phone 74191 0
+64 09 921 9999 ext 7842
Fax 74191 0
Email 74191 0
caryn.zinn@aut.ac.nz
Contact person for scientific queries
Name 74192 0
Dr Caryn Zinn
Address 74192 0
Auckland University of Technology
Private Bag 92006
Northcote
Auckland
1020
Country 74192 0
New Zealand
Phone 74192 0
+64 09 921 9999 ext 7842
Fax 74192 0
Email 74192 0
caryn.zinn@aut.ac.nz