The GluCoast Research Study
Kia ora, Kia orana, Talofa, Malo e lelei, Fakaalofa atu, Malo ni
This is a research study to find out how two different dietary approaches (or ways of eating) affect blood glucose control in people with type 2 diabetes. We also want to learn about people’s experiences of following these different approaches.
One dietary approach is called partial meal replacement. This involves replacing two of your usual meals with two meal replacement products (provided by us) each day. The other dietary approach is called time-restricted eating. This involves eating within a 9-hour ‘eating window’ that must finish by 7pm. We would help you to choose this window. For example, you might decide to only eat between 10am and 7pm, or you might decide to start eating at 8am and finish eating by 5pm.
We are currently looking for eligible people to take part in the GluCoast: Dietary strategies for glucose control in type 2 diabetes study.
If you are interested in participating in this study please click on the button here to register your interest and find out if you are eligible to take part:
Who can join the study?
We aim to have 30 people join this study who:
- Live on the West Coast of the South Island
- Have type 2 diabetes
- Have a BMI of 25 kg/m2 or more (we will calculate this for you)
- Are not using insulin to treat their diabetes
Why join the study?
Your blood glucose control may be improved by joining this study (though there is no guarantee of this).
You will be contributing to research that helps us understand how to improve nutrition recommendations for people with type 2 diabetes.
The study is free to join. After completing both interventions, you will receive a $200 grocery voucher. You will also be offered a personalised review of your blood glucose results (measured using continuous glucose monitoring, or CGM) and nutrition, with GluCoast researcher and Associate Registered Nutritionist, Kate Campbell.
What do the two dietary approaches involve?
The partial meal replacement approach involves replacing two of your usual meals with meal replacement products, on as many days as possible, for two weeks. We will provide these meal replacement products to you at no cost. The meal replacement products include shakes, porridge, soups, and meals in a variety of different flavours. Other than replacing two of your usual meals, you don’t need to change anything else about your eating.
The time-restricted eating approach involves eating all of your usual food and drink within a nine-hour ‘eating window’ ending no later than 7pm, on as many days as possible, for two weeks. You don’t need to change what or how much you are eating, just the timing of your eating. We will help you to decide on the timing of your eating window. Outside of this window, you can still have zero-energy drinks (e.g. water, black tea or coffee, or sugar-free soft drinks).
What happens if I join the study?
It does not cost you anything to join this study.
If you decide to join the study, we will ask you to come to a total of five study visits over about eight weeks. We expect each visit to take about 30–60 minutes. We can be flexible with scheduling your visits, so don’t worry if you can’t be available for eight weeks in a row. He Kai Ora, He Oraha Manawa
At Visit 1, you will:
- Have any questions you have about participating in the study answered
- Complete a consent form
- Answer questions about you and your lifestyle (e.g. ethnicity, physical activity)
- Have measurements taken (e.g. weight and blood pressure)
Over the next two weeks, we will ask you to:
- Eat, drink, and exercise normally
- Wear a CGM sensor
- Fill in a food diary for 3 days
- Fill out a short daily checklist
- Go for a blood test
At Visit 2, you will:
- Repeat some questions about you and your lifestyle
- Have measurements taken (e.g. weight and blood pressure)
- Find out which dietary approach you will follow first. The order that you will try the two approaches is completely random. You don’t get to choose which you do first.
Over the next two weeks, we will ask you to:
- Follow the first dietary approach (time-restricted eating or partial meal replacement)
- Exercise as normal
- Wear a CGM sensor
- Fill in a food diary for 3 days
- Fill out a short daily checklist
At Visit 3, you will:
- Repeat some questions about you and your lifestyle
- Have measurements taken (e.g. weight and blood pressure
- Do a short interview about your experiences with the first dietary approach
Over the next two weeks (or longer if needed), we will ask you to:
- Take a break from the study!
At Visit 4, you will:
- Repeat some questions about you and your lifestyle
- Have measurements taken (e.g. weight and blood pressure)
- Find out about the second dietary approach (time-restricted eating or partial meal replacement)
Over the next two weeks, we will ask you to:
- Follow the second dietary approach (time-restricted eating or partial meal replacement)
- Exercise as normal
- Wear a CGM sensor
- Fill in a food diary for 3 days
- Fill out a short daily checklist
At Visit 5, you will:
- Repeat some questions about you and your lifestyle
- Have measurements taken (e.g. weight and blood pressure)
- Do a short interview about your experiences with the two dietary approaches
- Receive a $200 grocery voucher
- Be offered a personalised review of your blood glucose (CGM) and nutrition (food diary) results
I’m worried I won’t be able to stick to each approach perfectly. Can I still take part?
Yes, absolutely you can still take part. One of the reasons we are running this study is to find out how you go with following these dietary strategies. Maybe they aren’t that realistic for some people and that is good to know, so we are interested in asking you questions about how you found both of these approaches.
What equipment do I need to be part of this study?
You don't need any special equipment, you just need an email address and/or a phone number we can contact you on. If you have internet access, we may ask you to complete some questionnaires online, in your own time. We will provide everything else that is required, including the meal replacement products, at no cost to you.
What is a food diary?
You will be asked to record everything you eat and drink for three full days at the start of the study, and once during both of the two week interventions.
We will ask you to record your food diary using either the Easy Diet Diary app on your smartphone, or on paper if you prefer (or do not have a smartphone). If you don't enjoy filling out details on what food you have eaten, this study may not be for you. We will help you to set up and learn to use the Easy Diet Diary app.
Click here for instructions on setting up and using the Easy Diet Diary app.
Click here for instructions on completing a paper food diary.
What is a CGM?
‘CGM’ stands for continuous glucose monitoring. A CGM sensor is a small device which you wear on the back of your arm. The sensor continuously measures the amount of glucose in your blood. In this study, we will ask you to wear a CGM sensor at for two weeks at each of three different time points:
- The first two weeks of the study (your usual eating habits)
- The two weeks of time restricted eating
- The two weeks of partial meal replacement
You will not be able to see the readings from the CGM sensor we provide during the study. However, you will be able to review your CGM results at the end of the study if you wish to. If you normally wear your own CGM to monitor your glucose levels, we will ask you to stop doing this for the duration of the study. It is important you continue with your usual diabetes self-management throughout this study.
Where do I go for my study visits?
Study visits will be held in the Pact building at 54 Tainui Street, Greymouth. The entrance is right on the corner, next to Development West Coast (see photo below).
Go to the reception area, where Kate will meet you when it is time for your appointment.
Where do I go to get a blood test?
You will go to Te Nīkau Hospital & Health Centre blood test services (phlebotomy) for your blood test. This is in the Community Services building located at the south-western corner of the Te Nīkau Hospital campus in Greymouth. We will provide you with a lab form. There is no need to book or call ahead. Just show up on a weekday morning with your lab form, and do NOT eat beforehand. This means nothing to eat or drink except plain water, for at least 8 hours before the blood test so that it is a fasting blood test. Please take your usual morning medications before the blood test.
Te Nīkau Hospital website (with map):
Participant information sheet and consent forms
Please read the participant information sheet to find out more about the study.
Meet the research team
 Andrew Reynolds Senior Research Fellow, Department of Medicine |  Meredith Peddie Senior Lecturer, Department of Human Nutrition |  Kate Campbell PhD student, Department of Medicine & Department of Human Nutrition |
How is the research funded?
Who can I contact about the study?
If you have any questions about the study, you can contact the GluCoast research team by email. You can also contact the researchers directly by phone.
Email: glu.coast@otago.ac.nz
Kate Campbell, Student Investigator
Phone: 021 279 1490
Dr Andrew Reynolds, Principal Investigator
Phone: 027 956 5826