Please note the ANZCTR will be unattended from 21/12/2018 until 08/01/2019. During this time no submissions or updates will be processed. Please ensure all trials are submitted/updated as soon as possible if you wish for them to be reviewed prior to the unattended period.

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
Trial registered on ANZCTR


Registration number
ACTRN12615001004550
Ethics application status
Approved
Date submitted
4/06/2015
Date registered
25/09/2015
Date last updated
19/01/2018
Type of registration
Prospectively registered

Titles & IDs
Public title
Effects of sugar-sweetened drinks on psychological and metabolic outcomes.
Scientific title
Possible effects on healthy young adults of sugar- and artificially-sweetened drinks in terms of psychological and metabolic outcomes
Secondary ID [1] 286782 0
Nil
Universal Trial Number (UTN)
U1111-1170-4543
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Posible metabolic and psychological effects of sugar drink consumption 295159 0
Condition category
Condition code
Diet and Nutrition 295395 295395 0 0
Other diet and nutrition disorders
Metabolic and Endocrine 295396 295396 0 0
Diabetes

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Participants are randomly assigned to 3 arms: (1) Sugar group: 4.5L of sugar-sweetened drink per week; (2) Diet group: 4.5L of artificially-sweetened drink per week; (3) Water group: 4.5L of bottled water. Intervention is for 12 weeks. During this period all participants are required to abstain from consuming sweetened drinks other than those given to them.
Notes:
1. a) The sugar-sweetened drinks will be commercially available carbonated beverages with sucrose content in the range 9% - 11%. Participants in this arm will be offered a choice between CocaCola, PepsiCola, Sprite and Fanta.
Participants in the Diet arm will be offered a choice between the equivalent sugar-free commercial beverages; e.g. Diet Coke, Coke Zero, Diet Pepsi, Sprite Light, which contain artificial sweeteners that can include aspartame, sucralose or stevia, or some combination.

b) Participants will be asked to consume no more than 3 of the 375-ml cans per day; otherwise it is up to them to decide when to consume their drink.

c) Monitoring of adherence to drinking all 12 cans each week consists of: 1.requiring that participants return the empty cans when they come to collect the next week's supply; and 2. reporting each week what beverages they have consumed in the previous week by completing the Brief 15-item Beverage Questionnaire (BEVQ-15) on each visit to the laboratory.

2. Participants are not asked to change their normal diet other than comply with the instructions on beverages; i.e. there are no further dietary restrictions.
Intervention code [1] 291937 0
Lifestyle
Intervention code [2] 292453 0
Treatment: Other
Comparator / control treatment
As indicated above, the Control treatment is to provide these participants with bottled water (Water group).
Control group
Active

Outcomes
Primary outcome [1] 295138 0
Change in cognitive function as measured by neuropsychological tests: the Logical Memory test and the Controlled Oral Word Association Test (COWAT).
Timepoint [1] 295138 0
Change from baseline (Initial test) at the start of the intervention to the Midway test 6 weeks later, to the Completion test 12 weeks after the start of the intervention, with a Follow up test approximately 12 weeks after the Completion test.
Primary outcome [2] 295139 0
Waist circumference
Timepoint [2] 295139 0
Change from baseline (Initial test) at the start of the intervention to the Midway test 6 weeks later, to the Completion test 12 weeks after the start of the intervention, with a Follow up test approximately 12 weeks after the Completion test.
Secondary outcome [1] 314838 0
Body mass index (BMI).
Timepoint [1] 314838 0
Change from baseline (Initial test) at the start of the intervention to the Midway test 6 weeks later, to the Completion test 12 weeks after the start of the intervention, with a Follow up test approximately 12 weeks after the Completion test.
Secondary outcome [2] 314839 0
Go/No go test for response inhibition (GNG).
Timepoint [2] 314839 0
Change from baseline (Initial test) at the start of the intervention to the Midway test 6 weeks later, to the Completion test 12 weeks after the start of the intervention, with a Follow up test approximately 12 weeks after the Completion test.
Secondary outcome [3] 316414 0
Change in metabolic function as measured by an Oral Glucose Tolerance Test (OGTT) in which blood sugar levels are measured at 15, 30, 45 and 60 min after consumption of 50g of glucose (dissolved in tap water) within 5 min.
Timepoint [3] 316414 0
Change from baseline (Initial test) at start of intervention to the Completion test 12 weeks later. NB The OGTT will not be administered in the Midway test or the Follow up test.
Secondary outcome [4] 316415 0
Total body fat, as measured by Bio-electrical Impedance Analysis.
Timepoint [4] 316415 0
Change from baseline (Initial test) at the start of the intervention to the Midway test 6 weeks later, to the Completion test 12 weeks after the start of the intervention, with a Follow up test approximately 12 weeks after the Completion test.
Secondary outcome [5] 316416 0
Sweetness preference test
Timepoint [5] 316416 0
Change from baseline (Initial test) to Completion test 12 weeks later.
Secondary outcome [6] 316461 0
Blood pressure
Timepoint [6] 316461 0
Change from baseline (Initial test) at the start of the intervention to the Midway test 6 weeks later, to the Completion test 12 weeks after the start of the intervention, with a Follow test approximately 12 weeks after the Completion test.
Secondary outcome [7] 316462 0
Biochemical assays of fasting blood sample, including blood glucose, triglyceride, cholesterol and uric acid levels.
Timepoint [7] 316462 0
Change from baseline (Initial test) to Completion test 12 weeks later.

Eligibility
Key inclusion criteria
Healthy volunteers in the age range 18-35 years and with BMI in range 17.5-30 who regularly drink at least 2L of sugar-sweetened drinks per week.
Minimum age
18 Years
Maximum age
35 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Previous or current eating-related disorder; current mental health diagnosis; diabetic; food allergies or other disorder affecting either diet or memory

Study design
Purpose of the study
Educational / counselling / training
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
If an initial phone call indicates that a potential participant meets the above criteria, s/he is invited to a screening session that includes measurement of BMI and blood pressure. If these and a further health questionnaire fail to reveal any health risk, then s/he is booked for Test session 1 (Baseline). Neither participants nor researchers will know which arm a potential participant will be allocated to until after a decision about eligibility has been made.

Provisional allocation of a participant to an arm will be made on arrival for Test session 1. Block randomisation will use a random number generator for each blocks of 6 participants (2 for each group).

This process will be constrained by attempting to match the groups in terms of 4 participant characteristics; in order of priority these are : 1. BMI; 2. Initial report of sugar-sweetened beverage intake, as measured by the Hedricks BEVQ-15; 3. Proportion of sweet energy-rich foods in their normal diet, as measured by the DFS short questionnaire; 4. Gender. It may well turn out to be impossible to stratify for more than the first two factors.

Allocation is not concealed.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Provisional allocation of a participant to an arm will be made on arrival for Test session 1. Participants will be randomised in blocks of 6 (2 for each group), with the order within each block determined by a random number generator.
This process will be constrained by attempting to match the groups in terms of 4 participant characteristics; in order of priority these are:
1) BMI;
2) Initial report of sugar-sweetened beverage intake, as measured by the Hedricks BEVQ-15;
3) Proportion of sweet energy-rich foods in their normal diet, as measured by the DFS short questionnaire;
4. Gender.
It may well turn out to be impossible to stratify for more than the first two factors.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint(s)
Safety
Statistical methods / analysis
In a convenience sample, Francis and Stevenson (2011) found that a self-reported HFHS diet reduced performance on the Logical Memory test relative to a self-reported LFS diet with an effect size of d=0.81. In order for us to have 80% power to detect a significant effect of our dietary intervention of a slightly more conservative effect size of d=.70 and with a=.05 (two-tailed), a sample size of 34 per group is required. Based on Maersk et al’s (2012) dietary intervention, we anticipate an attrition rate of 33%. Therefore, we will aim to recruit and randomise a total of 153 participants to achieve a final sample of 34 per group.
Analyses will be conducted per protocol on those participants who complete the first three tests. (Since a high drop out rate is expected for the final, 'follow up' test, data from this test will be treated separately.) If a particular participant has less than 5% missing data, then s/he will be considered a 'completer' and the missing data will be imputed via multiple imputation. Per protocol analysis is chosen because the study aims to assess the effects of the consumption of the three drinks and this requires that the participants actually consume the drinks that have been allocated to them.
The primary outcome, Logical Memory, will be analysed at Test 2, Test 3 and Test 4, separately via ANCOVAs, controlling for baseline Logical Memory scores (at Test 1).

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)
NSW
Recruitment postcode(s) [1] 9760 0
2006 - The University Of Sydney

Funding & Sponsors
Funding source category [1] 291410 0
Government body
Name [1] 291410 0
Australian Research Council
Address [1] 291410 0
GPO Box 2702
CANBERRA
ACT 2601
AUSTRALIA
Country [1] 291410 0
Australia
Primary sponsor type
Individual
Name
Professor Robert Boakes
Address
School of Psychology (A18),
University of Sydney,
NSW 2006,
Australia.
Country
Australia
Secondary sponsor category [1] 290086 0
University
Name [1] 290086 0
University of Sydney
Address [1] 290086 0
University of Sydney,
Sydney, NSW 2006
Country [1] 290086 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 292958 0
University of Sydney Human Research Ethics Committee
Ethics committee address [1] 292958 0
Research Office,
University of Sydney,
Sydney, NSW 2006
Ethics committee country [1] 292958 0
Australia
Date submitted for ethics approval [1] 292958 0
Approval date [1] 292958 0
17/04/2015
Ethics approval number [1] 292958 0
2015/074
Ethics committee name [2] 292959 0
Sydney Local Health District Clinical Trials Subcommittee
Ethics committee address [2] 292959 0
Research Development Office,
Level 8, Building 14,
Royal Prince Alfred Hospital,
Camperdown, NSW 2050
Ethics committee country [2] 292959 0
Australia
Date submitted for ethics approval [2] 292959 0
Approval date [2] 292959 0
16/02/2015
Ethics approval number [2] 292959 0
X14-0366

Summary
Brief summary
Background. Various lines of evidence indicate that negative metabolic consequences follow when a person regularly drinks a large quantity of sugar-sweetened beverages (SSBs). What is not known is whether SSBs also produce negative psychological effects, such as impairments in short-term memory and increased impulsiveness. Switching from SSBs to ‘diet’ beverages (non-nutritive sweetened beverages; NSBs) would seem to offer a relatively easy dietary change. However, it has been claimed that this can be counter-productive in at least some circumstances.
Aims. 1. To test whether SSB consumption produces impairment on psychological tests, relative to NSB consumption and a water control condition; 2. To test whether the effects of NSB consumption depends on other aspects of a person’s diet (e.g. consumption of sweet energy-rich foods).
Design. In a non-blinded 3-group parallel design over a 12-week period the Sugar group is given SSBs, the Diet group is given NSBs and the Water group is given water. Metabolic and cognitive/behavioural measures are taken at the outset of the intervention (Initial test), after 6 weeks (Midway test), at the end of the intervention (Completion test) and approximately 12 weeks later (Follow up test).
Main predictions: 1. In the Completion test the primary psychological outcome measure, scores on the Logical Memory test, will be lower in the Sugar group than in the other two groups. 2. In the Completion test the primary metabolic outcome, waist:hip ratio will be larger in the Sugar group than in the other two groups.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 57506 0
Prof Robert A. Boakes
Address 57506 0
School of Psychology (A18),
University of Sydney,
NSW 2006
Country 57506 0
Australia
Phone 57506 0
(612) 9351 3347
Fax 57506 0
Email 57506 0
bob.boakes@sydney.edu.au
Contact person for public queries
Name 57507 0
Prof Robert A. Boakes
Address 57507 0
School of Psychology (A18),
University of Sydney,
Sydney
NSW 2006
Country 57507 0
Australia
Phone 57507 0
(612) 9351 3347
Fax 57507 0
Email 57507 0
bob.boakes@sydney.edu.au
Contact person for scientific queries
Name 57508 0
Prof Robert A. Boakes
Address 57508 0
School of Psychology (A18),
University of Sydney,
Sydney
NSW 2006
Country 57508 0
Australia
Phone 57508 0
(612) 9351 3347
Fax 57508 0
(612) 9351 2603
Email 57508 0
bob.boakes@sydney.edu.au

No data has been provided for results reporting
Summary results
Not applicable