Low carb, no carb, good carbs… the carb debate rages on. Everyone seems to have an opinion on how much carbohydrate you should be eating when living with diabetes and it seems you have to pick a side to be on.

What do I mean by this? On one side you have those portrayed as following ‘traditional’ medical advice, whereby carbohydrates (carbs) are seen as a key part of someone’s diet to give them energy and important nutrients. It can be viewed as traditional thinking; a rigid approach that’s not open to new research.

At the other end of the spectrum you have the ‘low-carb movement’. People who are fall into this camp believe that eating moderate or greater amounts of carbohydrates is the likely root cause of chronic conditions and poor health in our society.

How much carbohydrate should someone living with diabetes eat?

Humans like black and white answers. However, in the world of nutrition this type of thinking is limiting.

In trying to get more comfortable with this, we need to create space for the shades of grey. This means recognising there are multiple dietary approaches that can achieve similar outcomes for living well with diabetes. What is right for one person could also be detrimental to another.

Health professionals, such as dietitians and diabetes educators, can offer a person living with diabetes guidance on how many carbohydrates they need for their nutritional requirements. But there is currently no specific recommendation in Australia to suit all people living with diabetes. Welcome to the uncomfortable world of grey.

In order to answer the question of knowing when you don’t have enough carbohydrates in your diet to meet your nutritional and health needs, we need to highlight some facts about carbohydrates.

Carbohydrate facts

• Some carbs are rich in nutrients that help your body function in many ways. While others contain little more than refined sugars or starches, and possibly also contain a number of other less health-supportive nutrients that can compound health issues.
• When current health guidelines promote eating a moderate about of carbohydrates, this does not include sources from added sugar or from foods classed as discretionary choices. Currently, an average Australian adult each day consumes one-third of their diet from this discretionary group (1).
• Both carbohydrates from natural sugar and starch sources contain valuable and essential nutrients to health. These include fibre, B vitamins, calcium, vitamin D, as well as antioxidants and phytochemicals.
• The amount of carbohydrate required for each person living with diabetes is different. The human body is complex and unique. We are each faced with different body sizes, lifestyles, medical histories, genetics and of course preferences.

Signs of not eating enough carbohydrates

If you are concerned that you are not eating enough carbohydrate, below is a list of symptoms or clues that your current diet may need some adjustment. These clues are a guide only. Some of these symptoms may be caused from other issues. For exampe, iron deficiency, not taking enough or taking too much insulin/medications, medication side-effects or interactions, as well as illness and other underlying medical conditions.

Low energy/ mood changes

You constantly feel tired, lack concentration for daily tasks or don’t seem to have enough energy to exercise. Humans have evolved to preference carbohydrates as the initial fuel the body burns to give us energy. Yes, there are other ways of accessing energy from foods in the form of protein and fat; however, it is not our evolutionary preference. If carbohydrate intake is not matched to your energy needs, your muscle and brain cells run short of their preferred fuel (glucose) and fatigue sets in. This may be felt more acutely in those who lead more active lifestyles.

It is also important to consider that is it not just the macronutrient carbohydrate in carbohydrate-rich foods that is important for energy production. Many micronutrients such as B vitamins, magnesium and choline, all play a role in energy production pathways (2). There is clear evidence to suggest low carbohydrate diets have a much greater risk of micronutrient deficiencies. This needs to be carefully considered (3).

It is imperative for people living with diabetes to be informed about the risks of a low carbohydrate eating plan, because reducing the carbohydrate load in your diet without adjusting particular medicines can result in very low blood glucose levels and or hypoglycaemia. If you are planning to begin a low carb eating plan, please discuss with your healthcare team before starting to be across these risks.

Digestion issues

When all sources of carbohydrates are removed, the digestive system is often the first indicator things are not quite right. This usually manifests in the form of constipation or diarrhoea. The key nutrient to maintaining healthy bowels and digestion is fibre. Both soluble and insoluble forms of fibre help to remove waste and regulate the speed of digestion and bowel transit time. Although some fibre can be obtained by non-starchy vegetables, it is much more difficult for people following a low carbohydrate diet to meet their daily fibre requirements.

Lowered immune function

The quality and response of your immune system is based on numerous aspects, beyond just that of your diet. It includes factors such as your age, exposure to physiological and psychological stress, sleep, exercise and smoking. However, a strong link has been established between your gut microbiota (gut bacteria) and your immune system. From a nutrition point of view, we need to consume foods that can diversify our healthy gut bacteria.

Both probiotics and prebiotics are required to make this happen. Probiotics are the healthy bacteria found in your gut and are gained from fermentable foods. Prebiotics are found in carbohydrate foods containing fibre and resistant starch, and allow the probiotics to grow and flourish. By not consuming these prebiotic foods, it can disturb the delicate balance inside your guts and in turn make you more susceptible to illness and disease, both in the short and long term.

To add to this picture, many micronutrients also play a role in protecting your immune system. Vitamins A, C, E as well as selenium are among some of the key micronutrients found in many carbohydrate-rich foods. They play a large role in protection as their antioxidant properties allow free radicals in the body to be neutralised. This, in turn, reduces your risk for certain diseases.

Constant hunger and food cravings

When a significant amount of carbohydrate food is removed from the diet, you might be left feeling a great sense of hunger. This can be due to the removal of the carbohydrates themselves, or it could actually be due to a reduced amount of total energy (calories) to allow your brain and body requires to operate optimally.

Hunger and some food cravings are an extremely important body response/cue to survive and function well physically and mentally. It is similar as the cue to go to the toilet. Being in a constant state of hunger can have serious negative effects on both physical and mental health and wellbeing. Hunger cues can also be affected by some medications (i.e. insulin) and innate or learned coping strategies. Speak with your healthcare team if you have concerns.

What’s right for you?

Working out how much carbohydrate is right for your diabetes is a very individualised question. It is therefore extremely important to connect in with your health professional team, specifically a dietitian, to help tailor this to you. You may also enjoy attending a free carb smart class that will give you more information on understanding carbs and diabetes. For further general questions on this article feel free to call us on 1300 342 238  and speak with an Accredited Practising Dietitian (APD). Otherwise, we recommend speaking to your GP about making a booking with an Accredited Practising Dietitian in the community  through your chronic disease management plan and referral pathway.

References

1. Australian Bureau of Statistics (2018). National Health Survey: First Results, 2017–18. ABS cat. no. 4364.0.55.001. Canberra: Australian Bureau of Statistics.
2. National Health and Medical Research Council (2020). Nutrient reference values for Australia and New Zealand. Retrieved from: https://www.nrv.gov.au/
3. Churuangsuk, C., Griffiths, D., Lean, M., & Combet, E. (2019). Impacts of carbohydrate-restricted diets on micronutrient intakes and status: A systematic review. Obesity reviews : an official journal of the International Association for the Study of Obesity, 20(8), 1132–1147. https://doi.org/10.1111/obr.12857

Linda Uhr

Accredited Practising Dietitian and Diabetes Educator