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Trial registered on ANZCTR


Registration number
ACTRN12622001177741
Ethics application status
Approved
Date submitted
22/08/2022
Date registered
1/09/2022
Date last updated
28/05/2024
Date data sharing statement initially provided
1/09/2022
Date results information initially provided
28/05/2024
Type of registration
Prospectively registered

Titles & IDs
Public title
Altering the timing of breakfast and exercise to modify post-meal glucose concentrations: The Breakfast and Exercise Timing (BET) Study
Scientific title
A randomised crossover controlled trial to investigate how altering the time of breakfast and exercise modify post-meal glucose concentrations in people with type 2 diabetes.
Secondary ID [1] 307511 0
None
Universal Trial Number (UTN)
U1111-1280-1098
Trial acronym
BET
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Type 2 diabetes 326939 0
Condition category
Condition code
Metabolic and Endocrine 324125 324125 0 0
Diabetes

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Participants will be randomly allocated into the order to complete each of the different timings of breakfast (conditions: Early at 7:00 am, Mid at 09:30 am and Delayed at 12:00 pm) and will be asked to follow the prescribed breakfast time and exercise. In a free-living environment, we will provide the participants with Freestyle Libre Pro iQ continuous glucose monitors (CGM Pro iQ), physical activity monitors (ActivPAL), and a wrist-worn sleep monitors (Actiwatch Spectrum), participants will consume breakfast for 8 days at one of the three prescribed times, and in the final 4 days of each 8 days will be asked to complete 20 min brisk walk within 30 min to 1 h after starting breakfast. After 6 day washout periods (allowing for a new sensor), the second and third conditions will be conducted. Prior to commencing the intervention conditions, participants will complete a 6-day baseline period in which they will be free-living, recording their food diary, food photos and wearing the CGM Pro iQ, ActivPAL, and Actiwatch Spectrum.
Participants will attend the laboratory on a minimum of 5 occasions with a total of 4 hours across the visits. In the 3-hour pre-study visit (V0) we will provide the participant with a handbook, specifically designed for this study, with the monitor information (i.e., removing the activity monitors, retaining the glucose sensor if it detaches) and detailed recording sections for each day of the intervention. We will also provide participants with a calendar for the study conditions according to each randomisation and we will explain the overview of the study where breakfast and exercise advice will be provided. We will also explain to participants how to complete dietary recordings (e.g. taking images at each eating occasion). At the pre-study visit, we will test HbA1c to assure eligibility and type 2 diabetes diagnosis, we will do a mixed meal tolerance test (MMTT), and a Dual-energy-X-ray absorptiometry scan for body composition. Each of visits 1-4 will be ~20 minutes, and we will collect the participants food diary, provide participants with breakfast for the next condition, and fit new glucose and activity/sleep monitors. We will also remind them about the specifications for their next condition. We will individualize the breakfast for each participant according to their habitual breakfast, matching the 25% of their energy requirements according to the Schofield equation with a 1.3 physical activity factor.
Intervention code [1] 323974 0
Lifestyle
Comparator / control treatment
Active control: participants will act as their own control (crossover-controlled trial study)

We will compare incremental glucose area under the curve (iAUC) postprandial breakfast period of each condition (Early, Mid and Delayed) within each participant, with the Early (07:00 am) condition as the comparator.
Control group
Active

Outcomes
Primary outcome [1] 331940 0
2 h incremental glucose area under the curve (iAUC) postprandial breakfast period using Freestyle Libre Pro iQ Continuous Glucose Monitors (CGM).
Timepoint [1] 331940 0
Mean incremental area under the curve (iAUC) measured in 15-min increments over 2 hours after starting breakfast from the first 4 days of each condition (Early, Mid, Delayed), using the pre-meal glucose concentration as the baseline value (using the trapezoid method).
Secondary outcome [1] 411749 0
2 h glucose iAUC after walking for 20 minutes after breakfast using Freestyle Libre Pro iQ Continuous Glucose Monitors (CGM).
Timepoint [1] 411749 0
Mean iAUC measured in 15-min increments over 2 hours after starting breakfast from the second 4 days (days 5-8) of each condition (Early, Mid, Delayed), using the pre-meal glucose concentration as the baseline value (using the trapezoid method).
Secondary outcome [2] 411750 0
2 h glucose iAUC for the postprandial lunch period using Freestyle Libre Pro iQ Continuous Glucose Monitors (CGM).
Timepoint [2] 411750 0
Mean iAUC measured in 15-min increments over 2 hours post consumption of lunch from the first 4 days (days 1-4) of each condition (Early, Mid, Delayed), using the pre-meal glucose concentration as the baseline value (using the trapezoid method).
Secondary outcome [3] 411752 0
Total day (24-h) activity patterns (i.e., time spent sedentary (sitting), standing, moving, number of steps, number of sit to stand), assessed using ActivPAL (thigh-worn inclinometer).
Timepoint [3] 411752 0
Measured during the 6 days of baseline before each intervention and during the intervention days in each condition (Early, Mid and Delayed).
Secondary outcome [4] 411754 0
Dietary intake (total day) of energy, macronutrients, and micronutrients.
Timepoint [4] 411754 0
Measured during the 6 days of baseline before each intervention and during the intervention days in each condition (Early, Mid and Delayed) using Research Food Diary (and subsequently, Foodworks).
Secondary outcome [5] 411756 0
Exploratory measures of glycaemic variability via mean of postprandial glucose responses to meals using the continuous glucose Pro iQ monitor.
Timepoint [5] 411756 0
Measured during the 6 days of baseline before each intervention and during the intervention days in each condition (Early, Mid and Delayed).
Secondary outcome [6] 413159 0
Assess sleep duration using Actiwatch Spectrum.
Timepoint [6] 413159 0
Measured during the 6 days of baseline (or washout) before each intervention and during the intervention days in each condition (Early, Mid and Delayed).
Secondary outcome [7] 413331 0
Adherence to exercise prescription (i.e. post-breakfast exercise) assessed using ActivPAL (thigh-worn inclinometer).
Timepoint [7] 413331 0
Measured during 2-h post breakfast meal period for the second 4 days (days 5-8) compared to the first 4 days (days 1-4) of each condition (Early, Mid, Delayed).
Secondary outcome [8] 413332 0
Timing of dietary intake (i.e., eating occasions).
Timepoint [8] 413332 0
Measured during the 6 days of baseline (or washout) before each intervention and during the intervention days in each condition (Early, Mid and Delayed) using food photo timing and/or manual recordings, where required.
Secondary outcome [9] 413333 0
Assess sleep efficiency using Actiwatch Spectrum
Timepoint [9] 413333 0
Measured during the 6 days of baseline (or washout) before each intervention and during the intervention days in each condition (Early, Mid and Delayed).
Secondary outcome [10] 413466 0
Exploratory measures of glycaemic variability via standard deviation (SD) of postprandial glucose responses to meals using the continuous glucose Pro iQ monitor.
Timepoint [10] 413466 0
Measured during the 6 days of baseline before each intervention and during the intervention days in each condition (Early, Mid and Delayed).
Secondary outcome [11] 413467 0
Exploratory measures of glycaemic variability via coefficient of variation (CV) of postprandial glucose responses to meals using the continuous glucose Pro iQ monitor.
Timepoint [11] 413467 0
Measured during the 6 days of baseline before each intervention and during the intervention days in each condition (Early, Mid and Delayed).
Secondary outcome [12] 413468 0
Exploratory measures of glycaemic variability will be assessed as a secondary outcome. Peak of postprandial glucose response to meals using the continuous glucose Pro iQ monitor.
Timepoint [12] 413468 0
Measured during the 6 days of baseline before each intervention and during the intervention days in each condition (Early, Mid and Delayed).
Secondary outcome [13] 413469 0
Exploratory measures of glycaemic variability via time to peak of postprandial glucose responses to meals using the continuous glucose Pro iQ monitor.
Timepoint [13] 413469 0
Measured during the 6 days of baseline before each intervention and during the intervention days in each condition (Early, Mid and Delayed).
Secondary outcome [14] 413470 0
Exploratory measures of glycaemic variability via pre meal glucose concentrations using the continuous glucose Pro iQ monitor.
Timepoint [14] 413470 0
Measured during the 6 days of baseline before each intervention and during the intervention days in each condition (Early, Mid and Delayed).
Secondary outcome [15] 413476 0
Total 24 h glucose area under the curve (tAUC) for the 24-h periods including exercise compared to non-exercise
Timepoint [15] 413476 0
Measured during the 24-h periods for the second 4 days (days 5-8) compared to the first 4 days (days 1-4) of each condition (Early, Mid, Delayed).

Eligibility
Key inclusion criteria
- Community dwelling persons 30 – 65 years old.
- Diagnosed (by GP/Endocrinologist) with T2D, with an HbA1c between 6.5%-<10%, measured within 3 months of enrolment.
- Not currently taking sulphonylureas or insulin or more than 2 Oral Hypoglycaemic Agents.
- Able to travel to the Fitzroy campus independently
Minimum age
30 Years
Maximum age
65 Years
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
- Currently meeting physical activity guidelines (>150 min/week).
- Currently following a ketogenic (i.e., <50 g CHO/day) diet, or following a restricted time diet (i.e., TRE, alternate day fasting or other forms of intermittent fasting).
- Unwilling to consume breakfast for the study period.
- Unable to adequately complete dietary monitoring, habitual dietary monitoring period or eating breakfast at the prescribed times.
- Unable to adequately complete 20 minutes of brisk walking after breakfast.
- Shift workers (i.e., more than 1 shift per month between 10:00 pm and 5:00 am)
- Smokers, including e-cigarettes, tobacco or marijuana, or within 3 months of quitting
- History of psychotic disorder, or current diagnosis of other major psychiatric illness (e.g. mood disorder, eating disorder, substance use disorder); and diagnosed gastrointestinal conditions.
- Women who are pregnant, breastfeeding (within 24 wk).
- Currently taking diuretic medication (contraindication to fasting) or medications known to interact with glucose metabolism;
- Changed medications within 3 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)
Central randomisation by computer
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Permuted block randomisation
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Crossover
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
Statistical analysis will be performed using linear mixed models to compare between conditions with baseline measures of HbA1c and sex as covariates. Significance will be set at P<0.05 and will be conducted using SPSS (Version 25).

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
5/09/2022
Actual
4/10/2022
Date of last participant enrolment
Anticipated
27/03/2023
Actual
22/11/2022
Date of last data collection
Anticipated
30/05/2023
Actual
10/03/2023
Sample size
Target
14
Accrual to date
Final
14
Recruitment in Australia
Recruitment state(s)
VIC
Recruitment postcode(s) [1] 38070 0
3065 - Fitzroy

Funding & Sponsors
Funding source category [1] 311790 0
University
Name [1] 311790 0
Australian Catholic University, Exercise and Nutrition Research Group Funds
Country [1] 311790 0
Australia
Primary sponsor type
Individual
Name
Dr Evelyn Parr
Address
Mary MacKillop Institute for Health Research
Exercise and Nutrition Program
Level 5, 215 Spring Street, Melbourne
Victoria, Australia 3000
Country
Australia
Secondary sponsor category [1] 313287 0
Individual
Name [1] 313287 0
Prof John Hawley
Address [1] 313287 0
Exercise and Nutrition Research Program
Mary MacKillop Institute for Health Research
Level 5, 215 Spring Street
Melbourne 3000 VIC
Country [1] 313287 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 311233 0
Australian Catholic University Human Research Ethics Committee
Ethics committee address [1] 311233 0
North Sydney Campus PO Box 968 NORTH SYDNEY, NSW 2059
Ethics committee country [1] 311233 0
Australia
Date submitted for ethics approval [1] 311233 0
10/06/2022
Approval date [1] 311233 0
29/08/2022
Ethics approval number [1] 311233 0
2022-2741HC

Summary
Brief summary
The proposed study will be the first to compare the effects of "typical" breakfast timing (Early at 7:00 am, Mid at 09:30 am and Delayed at 12:00 pm conditions) and 20 minutes of exercise after breakfast on postprandial hyperglycaemia in free-living adults with Type 2 Diabetes (T2D) using continuous glucose monitors (CGM) in a 6-week randomised crossover-controlled trial. The hypothesis of this study is that altering the time of breakfast will modify postprandial hyperglycaemia, and that twenty minutes of brisk walking after breakfast will attenuate (lower) postprandial hyperglycaemia.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 120410 0
Dr Evelyn Parr
Address 120410 0
Exercise and Nutrition Research Program
Mary MacKillop Institute for Health Research
Level 5, 215 Spring Street
Melbourne 3000 VIC
Country 120410 0
Australia
Phone 120410 0
+61 3 92308278
Fax 120410 0
Email 120410 0
evelyn.parr@acu.edu.au
Contact person for public queries
Name 120411 0
Miss Anapaula Bravo Garcia
Address 120411 0
Exercise and Nutrition Research Program
Mary MacKillop Institute for Health Research
Level 5, 215 Spring Street
Melbourne 3000 VIC
Country 120411 0
Australia
Phone 120411 0
+61410531942
Fax 120411 0
Email 120411 0
anapaula.bravogarcia@acu.edu.au
Contact person for scientific queries
Name 120412 0
Dr Evelyn Parr
Address 120412 0
Exercise and Nutrition Research Program
Mary MacKillop Institute for Health Research
Level 5, 215 Spring Street
Melbourne 3000 VIC
Country 120412 0
Australia
Phone 120412 0
+61 3 92308278
Fax 120412 0
Email 120412 0
evelyn.parr@acu.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
Potentially identifiable information


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
No additional documents have been identified.