Diet and Diabetes

How does my diet affect my diabetes?

Type 2 diabetes mellitus (T2DM)  is a form of diabetes which is characterised by high blood glucose (BGL), insulin resistance and relative lack of insulin.  T2DM is primarily impacted on by what we eat, in particular the carbohydrates in foods.  When we ingest carbohydrate foods, our body digests it to break down into glucose (sugar) which is then released into our bloodstream.  This causes an increase in our BGLs, which then sends the message to the pancreas to release insulin.  Insulin is a hormone produced as a result of high blood sugar levels.  Insulin’s role is to take the glucose from the blood and store it into our cells so it can be used as energy (fuel).  

In T2DM, this cycle is altered (the insulin is unable to do its job effectively or there is insufficient insulin in the body) and therefore the glucose remains in the blood for longer than desired, hence high BGLs.  By eating less carbohydrates there is ultimately less glucose being digested and entering the blood stream and therefore reduces the BGLs.  

How can I change my diet to help my diabetes management?

The types of carbohydrates can also have an impact on this.  Examples of this are high glycemic index (GI) carbohdyates and low glcyemic index (GI) carbohydrates.  An example of a high GI food could be jelly beans or white bread.  When this is consumed, the body digests it into glucose very rapidly and there is a sudden increase in BGLs.  When low GI carbohdayrtes are consumed, such as an apple or multigrain bread, the body digests this carbohdayte at a much slower rate and there is a very slow, slight increase in BGLs, which sustains energy until the next meal.  So in summary, the amount and types of carbohydrates eaten can dramatically impact the management of BGLs in T2DM.

Carbohydrate foods include:

• bread, rice, cereal, pasta

• Starchy vegetables (potato, sweet potato, corn)

• Fruit

• Dairy products (except cheese)

• Beans and legumes

• Foods with added sugars (lolllies, chocolates, biscuits, cakes etc)

How much carbohydrate should I be eating each day?

This hugely depends on many factors such as in individuals level of physical activity, medications and insulin if applicable.  For an individual newly diagnosed T2DM who is taking no insulin and is otherwise healthy, a recommendation of a low carbohydrate diet would be advised.  A definition of this would be to aim for 50g or less of total carbohydrates daily.  

On the other hand, if this individual had been prescribed insulin, low GI carbohydrates would be advised at each meal, but would be monitored closely to ensure there was not an excess of carbohydrates consumed for the allocated insulin.  This would be monitored through regular BGL testing (before and after each meal) and ongoing dietitian support.  Below are some examples of carbohydrate counting.  Carbohydrate counting is 15g carbohydrates per portion of carbohydrate.  A portion of carbohydrates is:

• 1 cup of milk

• 200g yoghurt

• 1 apple

• 1 banana

• ½ cup potato

• 1 slice of bread

• 3 cruskits

• 12 hot chips

• 6 small squares of milk chocolate

The general rule to ensure carbohydrates are spread evenly throughout the day, is to have 2 portions of carbohydrates at meals and 1 at snacks.  However, for the first individual without insulin, a recommendation of 2-3 portions of carbohydrates daily would be recommended and monitored by a dietitian.

How can a dietitian help me manage my diabetes?

A dietitian can provide education around the mechanisms of your diabetes and help you understand the appropriate changes for you.  This may include a low carbohydrate diet or a diet that contains regular low GI carbohydrates that fuel your body and needs adequately while maintaining optimum BGLs.  Alongside this a dietitian can provide guidance and specific dietary recommendations to ensure your diabetes is managed to the best of your ability.  T2DM can be a lifelong, degenerative chronic disease and therefore it is important to have ongoing support as your needs evolve.  If T2DM is not managed, it has been shown to cause serious permanent damage to the body in particular to the nerves and blood vessels.  Common side effects of unmanaged T2DM include heart attack, stroke, kidney failure, blindness and peripheral neuropathy caused by damaged nerves.

If you are newly diagnosed or would like support to manage your diabetes, please get into contact with our team of dietitians today.