Diet

Most of the burden of disease due to poor nutrition in Australia is associated with eating too much energy-dense and relatively nutrient-poor foods, and eating too few micronutrient-dense foods, including vegetables, fruit and wholegrain cereals. Type 2 diabetes may arise in an individual as one consequence of these factors. 

Key dietary themes for people with type 2 diabetes are to:¹ 

• promote and support healthy eating patterns, emphasising a variety of nutrient-dense foods in appropriate portion sizes, to improve overall health and: 
  • achieve and maintain body weight goals 
  • attain individualised glycaemic, blood pressure and lipid goals 
  • delay or prevent the complications of diabetes 
  • address individual nutrition needs based on personal and cultural preferences, health literacy and numeracy, access to healthful foods, willingness and ability to make behavioural changes and existing barriers to change 
  • maintain the pleasure of eating by providing non-judgemental messages about food choices while limiting food choices only when indicated by scientific evidence 
  • provide an individual with diabetes the practical tools to develop healthy eating patterns rather than focusing on individual macronutrients, micronutrients or single foods. 

All people should be offered and encouraged to seek advice on medical nutrition therapy by referral to an accredited practising dietitian (APD). An APD can help people address core issues around nutrition, such as achieving sustainable healthy eating patterns and, where appropriate, healthy body weight (and, if needed, loss) by reducing energy intake (portion control and type of food). An APD can also assist with recipe modification, changing cooking techniques, label reading, eating out and understanding of fad diets. 

Glycaemic management and meal planning 

Assistance from an APD as part of a multidisciplinary team may help people adjusting their dietary intake. 

To influence the glycaemic response after eating, meal plans need to consider both the amount and quality of carbohydrates eaten. The total amount of carbohydrate consumed (compared with other macronutrients or the glycaemic index of the meal) may be the major dietary factor that contributes to high postprandial blood glucose levels.² Eating low-glycaemic-load foods instead of higher glycaemic index (GI) foods may modestly improve glycaemic management.³ 

Low GI foods include dense wholegrain breads, steel-cut oats, lower fat milk and yoghurt, minimally processed (eg wholegrain, low GI) breakfast cereals, pasta, Doongara rice, legumes and most fruits. Intake of high-carbohydrate, low-nutrient-dense foods, such as soft drinks, cakes and confectionaries, should be confined to infrequent, small amounts to reduce the risk of weight gain and a worsening cardiometabolic profile.³ 

There is evidence that nutrition education may be particularly important for the prevention of hypoglycaemia in people with type 2 diabetes on insulin or sulfonylureas. Consistent carbohydrate intake and education on quantities of carbohydrate consumed and spaced, regular meal consumption may help some people manage blood glucose levels and weight. Alternatively, adjusting or reducing carbohydrate content consumed may require supported glucose monitoring and medication dose adjustment to prevent hypoglycaemic events, especially if fasting or using sulfonylureas or insulin. The inclusion of snacks as part of a person’s meal plan should be individualised and should be balanced against the potential risk of weight gain and/or glycaemic variability.⁴ 

Diabetes-specific nutritional formulas (DSNFs) are specialised supplemental nutritional therapies for people with diabetes that are not specific for weight management, but are supportive in sustaining shorter-term healthy nutrient intake, improving glycaemic management when people are not able to sustain a healthy whole-food intake (eg postoperative nutrition support, using glucagon-like peptide-1 receptor agonists in weight management or with metabolic surgery). DSNFs can be implemented with the support of an APD who will provide guidance on their appropriate use, including dosage, frequency and duration, while considering an individual’s overall dietary intake and health needs. An APD as part of the multidisciplinary diabetes team can support people with advice on any necessary changes to medications with the use of DSNFs, as well as how to practically transition back to a whole-food diet. 

The Australian Diabetes Society (ADS) has released a position statement with practical advice on DSNFs.⁵ 

Certain dietary approaches have evidence to support individual cardiovascular risk reduction, including the Dietary Approaches to Stop Hypertension (DASH) diet and Mediterranean diet.⁶ 

Evaluation of current dietary intake and the eating patterns of an individual is an initial critical step to support the management of type 2 diabetes.⁷ It remains an important initial step on diagnosis of diabetes and should be reviewed regularly as part of ongoing management. 

Dietary habit changes are often slow and incremental. There is no need for a ‘special’ diet for diabetes, just the requirement to consider a sustainable, sensible, balanced eating plan that is culturally appropriate for each individual. Keep advice simple and educate people about healthy food choices. Low and lower carbohydrate eating patterns can be beneficial for some individuals with type 2 diabetes, but they require careful planning and monitoring to ensure safety and effectiveness. It is important to tailor dietary interventions to individual needs and circumstances, in discussion with an APD. 

Identifying psychosocial issues around eating (eg binge eating, eating when stressed or bored) is also very important. Clinically assess people with diabetes about personal experiences with different dietary approaches and whether there have been any cycles of weight loss and gain, and identify any modifiable issues that impact upon healthy dietary adherence. 

Not all dietary sugars need to be eliminated. Small amounts of added simple carbohydrate as part of a high-fibre, modified-fat meal plan increases the choice of food available and may aid sustainability for dietary approaches and healthy adherence. Foods naturally high in sugars, such as fruit and dairy, do not need to be avoided in a balanced, individually managed diet. 

Referral to an APD and a credentialled diabetes educator⁸ will support implementation and reinforcement of these recommendations. A list of APDs in your area can be found on the Dietitians Australia website. 

Further information about diet for people with diabetes, including a position statement about low-carbohydrate diets for diabetes, can be found on the Diabetes Australia website. 

Further reading 

• Evert AB, Dennison M, Gardner CD, et al. Nutrition therapy for adults with diabetes or prediabetes: A consensus report. Diabetes Care 2019;42(5):731–54. doi: 10.2337/dci19-0014. 
• Davies MJ, D’Alessio DA, Fradkin J, et al. Management of hyperglycemia in type 2 diabetes, 2018. A consensus report by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD). Diabetes Care 2018;41(12):2669–701. doi: 10.2337/dci18-0033. 
• Marincic PZ, Salazar MV, Hardin A, et al. Diabetes self-management education and medical nutrition therapy: A multisite study documenting the efficacy of registered dietitian nutritionist interventions in the management of glycemic control and diabetic dyslipidemia through retrospective chart review. J Acad Nutr Diet 2019;119(3):449–63. doi: 10.1016/j.jand.2018.06.303. 
• Briggs Early K, Stanley K. Position of the Academy of Nutrition and Dietetics: The role of medical nutrition therapy and registered dietitian nutritionists in the prevention and treatment of prediabetes and type 2 diabetes. J Acad Nutr Diet 2018;118(2):343–53. doi: 10.1016/j.jand.2017.11.021. 
• Dobrow L, Estrada I, Burkholder-Cooley N, Miklavcic J. Potential effectiveness of registered dietitian nutritionists in healthy behavior interventions for managing type 2 diabetes in older adults: A systematic review. Front Nutr 2022;8:737410. doi: 10.3389/fnut.2021.737410. 
• Franz MJ, MacLeod J, Evert A, et al. Academy of Nutrition and Dietetics Nutrition practice guideline for type 1 and type 2 diabetes in adults: Systematic review of evidence for medical nutrition therapy effectiveness and recommendations for integration into the nutrition care process. J Acad Nutr Diet 2017;117(10):1659–79. doi: 10.1016/j.jand.2017.03.022.