Is a low carbohydrate diet effective for managing Type 2 Diabetes?


It’s no secret that eating well is essential for good health and wellbeing, especially as a healthy diet can assist with managing weight and stable blood glucose levels. However, what is considered a healthy diet for people with Type 2 Diabetes?



Well unfortunately this answer is not straightforward. Everyone’s nutritional needs are different so there are a number of approaches individuals can take to achieve good nutrition and manage their glucose levels. One popular approach for diabetes management is low carbohydrate diets (LCDs). As the name suggests, people following a LCD restrict their carbohydrate intake and rely on foods high in protein and fats for energy.


Let’s take a closer look at carbohydrates to better understand how this eating pattern may help manage diabetes.


What are carbohydrates?


Carbohydrates are a nutrient which fuels our bodies and has an important role in good gut health. Carbohydrates are found in a variety of foods like bread, fruit, vegetables, milk and also foods high in added sugar.


What is the link between carbohydrates and diabetes?


After eating a slice of bread for example, our digestive system breaks the carbohydrates down into smaller sugar molecules called glucose which is absorbed into our bloodstream (or stored in our liver and muscles). Normally, a hormone produced by the pancreas (insulin) acts like a key unlocking cells to accept glucose to provide us with energy. However, for people who have Type 2 Diabetes, their pancreas either does not produce enough insulin or their insulin produced does not effectively unlock cells. As a result, glucose builds up in the bloodstream, hence a high blood glucose level.


So if cells require glucose for energy, how can people with Type 2 Diabetes reduce their carbohydrate intake and stabilise their blood glucose levels? Let’s see what the research says!


What does the research tell us about low carb diets and diabetes management?


A recent meta-analysis (an analysis combining the results of multiple research studies) of 23 randomised clinical trials evaluated the effectiveness and safety of LCDs (<26% of total energy intake from carbohydrates) and very low carbohydrate diets (<10% of total energy intake from carbohydrates) for adults with Type 2 Diabetes (Goldenberg et al., 2021).


Reducing HbA1C to 6.5% (diabetes remission)

Eight of the 23 studies reported results regarding diabetes remission. LCD’s were beneficial at reducing HbA1C (a measure of average blood glucose levels over 8-12 weeks) by 32%. This remission was observed at a lower rate when LCDs were not accompanied with diabetes medication.


Achieving weight loss

18 studies showed that participants following LCDs achieved greater weight loss compared with low fat diets, around 7.5kg loss within six months.


Improving fasting blood glucose levels

LCDs achieved an average 0.73 mmol/L greater reduction in blood glucose levels compared with low fat diets at six months. However, no difference was observed at 12 months.


Although these results appear promising, issues regarding long term sustainability following a LCD remain as these health benefits either diminished at 12 months or were not reported by the researchers. Also, LCDs are not appropriate for some populations like children, women who are pregnant or breastfeeding and people taking certain diabetes medications (SGLT2 inhibitors) (Diabetes Australia, 2019). These limitations highlight the importance of seeking advice from a dietitian who can provide an individualised LCD for you and provide ongoing support and accountability.


Tips to help with following a low carbohydrate diet


If the above research has intrigued you and you’re thinking of giving a LCD a go, here are six simple strategies to keep in mind.


  1. Reduce your carbohydrate intake gradually as a sudden and extreme reduction may cause nausea, tiredness, constipation, headaches and muscle cramps.

  2. Do not completely remove carbohydrates from your diet as they are essential for a variety of nutrients like fibre for good gut health. Focus on unrefined and unprocessed carbohydrates like vegetables, wholemeal bread, legumes and fruit. Restrict ultra-processed and packaged sources of carbohydrates like chips, soft drinks, lollies, cakes and ice cream.

  3. Ensure foods high in fat are predominantly unsaturated like olive oil, avocado and peanut butter. Limit foods high in saturated fats like coconut oil and processed meats as recommended by the National Heart Foundation.

  4. Include a variety of protein rich foods like chicken, legumes, lean red meats, tofu, fish, seafood and nuts and seeds.

  5. Focus on low carbohydrate vegetables like cauliflower, green beans, tomatoes, zucchini, asparagus and broccoli. Aim to fill half your plate with these fibre-rich beauties!

  6. Closely monitor your blood glucose levels. Check them before and two hours following a meal to see improvement based on your dietary changes.

Remember, everyone’s nutritional needs are different and there is no one-size-fits-all approach for healthy eating with Type 2 Diabetes.


For personalised advice and strategies to implement an individualised LCD that is nutritionally complete, enjoyable, safe and sustainable for you, book an appointment at www.nourishadl.com/dietitian


Written by student dietitian, Charlotte Manning

Reviewed by dietitian, Rebecca Greco


References

Diabetes Australia. (2020). What Should I Eat. Retrieved from https://www.diabetesaustralia.com.au/food-activity/eating-well/what-should-i-eat/


Dietitians Australia. (2020). Carbohydrates- What You Need to Know. Retrieved from https://dietitiansaustralia.org.au/smart-eating-for-you/smart-eating-fast-facts/nourishing-nutrients/carbohydrates-what-you-need-to-know/.


Goldenberg, J. Z., Day, A., Brinkworth, G. D., Sato, J., Yamada, S., Jonsson, T., Beardsley, J., Johnson, J. A., Thabane, L., & Johnston, B. C. (2021). Efficacy and safety of low and very low carbohydrate diets for type 2 diabetes remission: systematic review and meta-analysis of published and unpublished randomized trial data. BMJ, 372, 1-13. doi: 10.1136/bmj.m4743


Wells, C., Russel, T., Bell, K., Flavel, R., Cooke, D., Clark, C., Robinson, J., & Hoekstra, M. (2019). Position Statement- Low Carbohydrate Eating for People with Diabetes. Australia: Diabetes Australia.


Subscribe to receive my weekly nutrition tips straight to your inbox