Trial Review

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
Help: Registration number
ACTRN12626001316392p
Ethics application status
Help: Ethics application status
Submitted, not yet approved
Date submitted
Help: Date submitted
23/09/2026
Date registered
Help: Date registered
2/11/2026
Date last updated
Help: Date last updated
2/11/2026
Date data sharing statement initially provided
Help: Data sharing statement date
2/11/2026
Type of registration
Help: Type of registration
Prospectively registered

Titles & IDs
Public title
How does a vegan diet high in ultra-processed foods impact cardiometabolic health?
Scientific title
The effect of ultra-processed plant-based diet on cardiometabolic health in adults: a single-arm feeding trial
Additional trial identifiers [1] 318508 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Related trial records

Health condition
Health condition(s) studied:
cardiometabolic health 343683 0
Condition category
Condition code
Metabolic and Endocrine 339804 339804 0 0
Diabetes
Cardiovascular 340041 340041 0 0
Other cardiovascular diseases

Intervention/exposure
Study type
Interventional
Description of the intervention or exposure
During the study, participants' diet will remain fully vegan. The study team will support participants in increasing the proportion of ultra-processed foods (UPFs) in their diet from 20-50% (selection criteria) to approximately 80% of total energy intake immediately upon commencement of the intervention (Day 1) and maintain it at this level for the remaining study period (4 weeks). As part of the dietary intervention, participants will independently purchase the required foods and store them in their own homes using appropriate household storage methods (e.g., pantry, refrigerator, or freezer as applicable). Examples of the UPFs include breakfast cereals, packaged bread, snack bars and meat/milk alternatives. Participants will receive a supermarket and meal guide, created specifically for this study, to support diet compliance. The guide contains the following sections:
1. How to identify a suitable vegan UPF
2. Easy ways to increase the proportion of UPFs
3. Example seven-day vegan menu
4. Examples of how to move towards approximately 80% UPFs
5. Product photo galleries by food category
The aim is mainly to replace lower-processed foods with suitable vegan UPF alternatives, rather than change the total energy intake.
A dietitian will be involved throughout the trial to personalise meal plans, ensure they suit each participant, and provide counselling via email and phone calls to support diet compliance. Participants will receive two emails (on days 7-10 and 20-23 of the study) requesting two 24-h dietary recalls (weekday and weekend) to assess dietary adherence, and they will receive calls from a dietitian. As with screening, they will complete a 24-h dietary recall using the Intake24 online system to assess adherence to the prescribed diet.
Intervention code [1] 335406 0
Lifestyle
Description of the comparator or control
No control group
Control group
Uncontrolled

Outcomes
Primary outcome [1] 346976 0
Insulin sensitivity and glycaemic regulation assessed together as a composite primary outcome.
Timepoint [1] 346976 0
Baseline and post-intervention (4 weeks)
Primary outcome [2] 346977 0
Blood pressure
Timepoint [2] 346977 0
Baseline and post-intervention (4 weeks)
Primary outcome [3] 347201 0
Arterial stiffness
Timepoint [3] 347201 0
Baseline and post-intervention (4 weeks)
Secondary outcome [1] 468451 0
Participants retention rate
Timepoint [1] 468451 0
Post-intervention (4 weeks)
Secondary outcome [2] 468452 0
Diet acceptability
Timepoint [2] 468452 0
Post-intervention (4 weeks)
Secondary outcome [3] 469452 0
Diet adherence
Timepoint [3] 469452 0
Post-intervention (4 weeks)

Eligibility
Key inclusion criteria
Eligible participants are men and women with a BMI of 25.0-29.9 kg/m², stable weight (within ±5% over the past 3 months), and currently following a 100% plant-based (vegan) diet with intake of ultra-processed foods of 20-50% of daily energy.
Minimum age
18 Years
Maximum age
40 Years
Sex
Both males and females
Healthy volunteers
No
Key exclusion criteria
Diabetes (Type 1 or Type 2), elevated fasting blood glucose levels (>6.0 mmol/L), history of cardiovascular disease (heart attack, stroke, atrial fibrillation, angina, stents), uncontrolled blood pressure (>140/90 mmHg), cancer in the last 5 years (except non-melanoma skin cancer), smoking or vaping for the past 12 months, high level of physical activity at baseline, food allergies, pregnancy, lactation, on medication that affects insulin sensitivity, blood glucose levels, blood pressure or lipids, and inability to read/speak/understand English.

Study design
Purpose of the study
Prevention
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Single group
Other design features
Phase
Not Applicable
Type of endpoint/s
Statistical methods / analysis
The sample size was based on detecting a 15% increase in insulin area under the time curve with the high-UPF diet, aiming for 80% power and a 5% significance level and accounting for 20% dropout.

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
2/11/2026
Actual
Date of last participant enrolment
Anticipated
4/10/2027
Actual
Date of last data collection
Anticipated
25/11/2027
Actual
Sample size
Target
20
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
VIC

Funding & Sponsors
Funding source category [1] 323085 0
Government body
Name [1] 323085 0
NHMRC Investigator grants
Country [1] 323085 0
Australia
Funding source category [2] 323086 0
University
Name [2] 323086 0
Deakin University Postgraduate Research Scholarship
Country [2] 323086 0
Australia
Primary sponsor type
University
Name
Deakin University
Address
Country
Australia
Secondary sponsor category [1] 326229 0
None
Name [1] 326229 0
Address [1] 326229 0
Country [1] 326229 0

Ethics approval
Ethics application status
Submitted, not yet approved
Ethics committee name [1] 321488 0
Deakin University Human Research Ethics Committee (DUHREC)
Ethics committee address [1] 321488 0
Ethics committee country [1] 321488 0
Australia
Date submitted for ethics approval [1] 321488 0
16/09/2026
Approval date [1] 321488 0
Ethics approval number [1] 321488 0

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 153874 0
A/Prof Katherine Livingstone
Address 153874 0
Deakin University, Melbourne Burwood Campus, 221 Burwood Highway, Burwood, Victoria 3125
Country 153874 0
Australia
Phone 153874 0
+61 3 924 45416
Fax 153874 0
Email 153874 0
[email protected]
Contact person for public queries
Name 153875 0
Katherine Livingstone
Address 153875 0
Deakin University, Melbourne Burwood Campus, 221 Burwood Highway, Burwood, Victoria 3125
Country 153875 0
Australia
Phone 153875 0
+61 3 924 45416
Fax 153875 0
Email 153875 0
[email protected]
Contact person for scientific queries
Name 153876 0
Katherine Livingstone
Address 153876 0
Deakin University, Melbourne Burwood Campus, 221 Burwood Highway, Burwood, Victoria 3125
Country 153876 0
Australia
Phone 153876 0
+61 3 924 45416
Fax 153876 0
Email 153876 0
[email protected]

Data sharing statement
Will the study consider sharing individual participant data?
No


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.