Assessing the role of supplements in diabetes management
By Rebecca McPhee, Accredited Practising Dietitan
With an expanding market of over-the-counter supplements, you may get questions from your clients about whether these products offer any genuine benefit, particularly in the context of glycaemic control and weight management. As the popularity of supplements such as meal replacement shakes and health products increases, it’s important to critically evaluate their efficacy, safety, and role within evidence-based diabetes care.
Consumer spending on non-PBS pharmaceuticals
According to 2020–2021 data from the Australian Institute of Health and Welfare (AIHW), Australians spent an average of $445 per person on non-PBS pharmaceuticals, including vitamins, supplements, and over-the-counter medicines. This is almost double the average amount individuals spent on dental services and significantly more the amount spent on allied health professionals such as chiropractors, optometrists, practice nurses and physiotherapists.
When might supplements be considered?
Nutritional supplements should not replace foundational components of diabetes management, such as a balanced diet, regular physical activity, and medication when prescribed. However, supplements may be appropriate where dietary intake is inadequate, there’s a malnutrition risk, or under medical supervision as part of a structured weight loss program.
Questions to discuss with your clients
- What their motivation is and what they expect the outcomes for supplement use to be?
- Have they trialled any other dietary or lifestyle interventions?
- Do they have any underlying nutritional gaps or unmet needs?
Key areas to consider when evaluating a supplement
- The safety and regulatory status of the supplement.
- Intended clinical benefit (e.g. glycaemic control, weight loss, cholesterol reduction)
- Product safety profile and possible drug interactions
- Scientific evidence supporting efficacy
- TGA approval (AUST R or AUST L classification)
- Potential side effects or contraindications
Regulation of supplements in Australia
All complementary medicines in Australia must be listed or registered with the Therapeutic Goods Administration (TGA). Products are classified as:
- AUST R: Registered medicines assessed for safety, quality, and efficacy.
- AUST L: Listed medicines (lower risk) assessed for safety and quality only.
Products lacking these identifiers are not legally approved for sale in Australia and may pose health risks, particularly if sourced online internationally.
Very Low-Calorie Diets (VLCDs) and meal replacements are governed by FSANZ (Food Standards Australia New Zealand) and not by the TGA, as they are classified as foods.
Evidence review of common supplements and meal replacements
Berberine
Berberine is a natural compound found in a variety of plants including barberry, goldenseal, Chinese goldthread and tree turmeric. It is available in capsules, soft gels, tablets, liquid, and powder form. Recently, information about berberine has gone viral, claiming to aid weight loss, manage blood glucose levels, improve insulin resistance, improve heart health (lower LDL cholesterol and triglycerides) and improve gut health.
Pros:
- Longstanding use in traditional Chinese medicine and Ayurveda
Cons:
- Common GI side effects such as flatulence, diarrhea, vomiting, nausea.
- Potential interactions with many medications including metformin, medications for heart disease, high cholesterol or high blood pressure, and medications for blood thinners such warfarin or medicines that cause drowsiness or sedation.
- Limited high-quality human research; evidence largely animal-based.
- Misleading marketing claims such as ‘natures Ozempic’. This claim is incorrect as berberine works differently and via different mechanisms in the body compared with Ozempic.
Clinical verdict: Not recommended due to insufficient evidence and risk of interactions.
Glycoguard™
Glycoguard™ is a dietary supplement claiming to support healthy blood glucose levels. The product is available in capsule form and contains berberine, cinnamon extract and chromium.
Cons:
- No TGA approval
- No published independent research to support the product
- Marketing relies heavily on social media and unverified endorsements
Clinical verdict: Not suitable; lacks scientific validation.
Glucerna®
Low-GI meal replacement formulated for people with diabetes, pre-diabetes, or impaired glucose tolerance. It is available in powder form (mix with water) or ready to drink liquid form. It can be used to replace a meal, partial meal, or snack, as part of a diabetes management plan including diet and exercise.
Pros:
- Backed by 30 years of research
- Includes slow-release carbs and prebiotics to help manage blood glucose levels
- Nutritionally complete with 28 vitamins/minerals
- Unique fat blend supports a healthy heart
- Enriched with prebiotic fibre to maintain a healthy digestive system
Cons:
- Contains sweeteners which may cause side effects to clients with irritable bowel syndrome.
- Vitamin E content may impact clients on anticoagulants
Clinical verdict: Suitable as a supplementary option within a structured diabetes management plan.
IsoWhey® Diabetic Formula
IsoWhey® Diabetic Formula is designed to support the nutritional needs of people with diabetes who cannot meet their needs through dietary modification alone.
Pros:
- Certified as low GI (GI 18)
- Fortified with 22 vitamins and minerals
Cons:
- Contains sweeteners which may cause side effects to clients with irritable bowel syndrome.
- Contains vitamin E (potential anticoagulant interaction)
Clinical verdict: Suitable as part of a diabetes management plan which includes whole food and exercise.
KicStart™ VLCD
A nutritionally complete meal replacement program for medically supervised weight loss.
Pros:
- Supported by independent clinical trials
- Shown to improve glycaemic control and support diabetes remission
- Full rebate available for eligible clients through some health funds
Cons:
- Requires medical oversight and medication adjustment
- Potential for short-term side effects with low-energy intake
Clinical verdict: Appropriate under medical supervision; transition back to whole food eating is essential.
OPTIFAST® VLCD
A nutritionally complete meal replacement used for people who are struggling to lose weight from diet and exercise alone.
Pros:
- Evidence supports low- and very low-energy meal replacement as a successful strategy for weight loss.
- Used in independent, published clinical trials that showed significant weight loss and health improvements including improved blood glucose control, improved blood pressure control, reduced cholesterol, reduced osteoarthritic pain and diabetes remission.
- Some health funds may provide a rebate.
Cons:
- Clinical supervision required
- Potential for short-term side effects with low-energy intake
Clinical verdict: Suitable. However, transiting back to whole food eating is essential.
Interested in learning more about managing diabetes?
Our Managing diabetes course bite provides practical guidance on managing diabetes, helping you support your patients with confidence. By completing the course you can:
- Describe how diabetes can be managed and the purpose and individual roles that comprise a Diabetes Care Team.
- Describe the Australian Guide to Healthy Eating, the plate model and additional recommendations for people living with diabetes.
- Describe the benefits of physical activity for diabetes management with reference to the Australian Guidelines for Physical Activity.
- Describe key actions of common oral medication groups used in diabetes management.
Enrol today and gain valuable knowledge, CPD points, and practical skills to enhance your professional practice.