Diabetes is a serious and complex condition where the body cannot produce or use insulin properly, causing high levels of glucose in the blood. There are three main types of diabetes - type 1, type 2 and gestational diabetes.

Type 1 diabetes is an autoimmune disease where the body's own immune system destroys the insulin-producing cells in the pancreas. Without the production of insulin, cells cannot take up and use glucose from the blood.

The exact cause is not known. Type 1 diabetes can occur at any age, but is most commonly diagnosed in children and adolescents, and requires lifelong management with insulin. There is no cure. 

Type 2 diabetes is more common and it is also largely preventable through diet and exercise. Here the body becomes resistant over time to the normal effects of insulin and/or loses the ability to produce enough insulin in the pancreas. 

We do not know exactly what causes type 2 diabetes. It is linked to lifestyle risk factors and genetics. Certain ethnicities, being overweight or obese, genetics, smoking and high blood pressure all increase a person's risk of developing type 2 diabetes. Insulin, medications and lifestyle interventions can all be used to help manage it.

Gestational diabetes is where high blood glucose levels appear during pregnancy in women who have no history of diabetes. It can cause complications during pregnancy and increases a mothers risk of developing type 2 diabetes later in life.

All types of diabetes are increasing, with type 2 growing at a faster rate and accounting for about 85% of all cases.  

Your diet and type 2 diabetes

Diabetes associations generally recommend lifestlye modification and medication for management of type 2 diabetes. Having a healthy diet and being active will help manage blood glucose levels and body weight. Advice for eating well with diabetes follows the general dietary guidelines for a healthy population. Individual meal plans can be helpful for tailored dietary advice.

To help manage diabetes, meals should be spread regularly throughout the day, and be low in saturated fat.

The role of sugar

Sugar itself is not proven to cause diabetes. Diabetes is caused by inadequate production or a lack of the hormone insulin. Insulin controls the level of glucose in the blood so watching your carbohydrate intake helps to achieve glycemic control. 

Being overweight increases the risk of type 2 diabetes so excess energy from any source which leads to weight gain should be monitored. The advice follows that of the dietary guidelines, to limit intakes of added sugars.

'Because diabetes effects blood glucose levels, many people think they need to avoid sugars and foods containing sugar. However, if eaten as part of a healthy meal plan, or combined with exercise, sweets and desserts can be eaten by people with diabetes. The key is to eat everything in moderation.' Diabetes Australia

There is no need to completely avoid sugars or for people with diabetes to focus on a sugar free diet. Sugars can be included in a moderate amount, as part of a healthy meal plan for people with diabetes. 

Glycemic index in diabetes 

Sucrose has a medium Glycemic Index (GI) (~60-65) and causes no greater swing in blood glucose than many other starchy carbohydrates. 

A low GI diet can have specific benefits for diabetes. Studies show a low GI diet can improve your glycemic control compared to a high GI diet. It can also provide improved insulin sensitivity, reduced insulin resistance, reduced risk of vascular disease, and greater weight loss when compared to other healthy diets.

Research now shows that a low GI diet can actually protect against Type 2 diabetes.

The GI of a particular food or meal can also be affected by the protein, fat and dietary fibre content, as well as the form in which foods are consumed (hot, cold or cooked).

See here for detailed information on GI 

Body weight and physical activity  

Type 2 diabetes is strongly linked to overweight and obesity, so it is important to have regular physical activity to maintain a healthy body weight. As well as helping the waistline, exercise will also lower your blood glucose levels, improve insulin sensitivity, and lower blood pressure, blood triglyceride levels and overall risk of heart disease.

People with diabetes are advised to have at least 30 minutes of moderate physical activity on most days of the week.

Type 2 diabetes naturally progresses to the use of tablets and insulin to help control blood glucose levels. The overall focus is to keep blood glucose within the target range. Monitoring blood glucose levels regularly helps identify whether the treatment is working or needs to be adjusted. If you can sucessfully do this, the risk of further complications down the track is reduced. 

Learn more in our fact sheet on sugars and diabetes here

REFERENCES

• Diabetes Australia. What should I eat? https://www.diabetesaustralia.com.au/what-should-i-eat 
• Diabetes New Zealand. Diabetes and healthy food choices pamphlet  https://www.diabetes.org.nz/pamphlet-ordering 
• Lean MEJ & Te Morenga L. (2016). Sugar and Type 2 diabetes. British Medical Bulletin, 120(1):43–53
• Rippe JM & Angelopoulos TJ. (2016). Sugars, obesity, and cardiovascular disease: results from recent randomized control trials. Eur J Nutr, 55:45-53
• Livesey G, Taylor R, Livesey HF, et al. (2019). Dietary glycemic index and load and the risk of type 2 diabetes: a systematic review and updated meta-analyses of prospective cohort studies. Nutrients, 11(6):1280.
• Livesey G, Taylor R, Livesey HF, et al. (2019). Dietary glycemic index and load and the risk of type 2 diabetes: assessment of causal relations. Nutrients, 11(6):1436.