What is fasting blood glucose?

A fasting blood glucose test determines the concentration of glucose circulating in your blood stream after a fast, or in other words, after not eating or drinking anything other than water for 8 – 12 hours. The test itself is used to diagnose diabetes, and is easy to perform, convenient and less expensive than other tests. It is therefore the preferred test for initial screening for blood sugar disorders.

Why measure fasting blood glucose?

When fasting, such as in the period between dinner and breakfast, your body still needs glucose for energy, even though you have not eaten. As a result, it produces a number of hormones which activate the release of glucose from the muscles, liver and other tissues. This increases blood glucose levels. To prevent blood glucose from going too high, this is followed by release of insulin, slowing glucose release and promoting its uptake and use. In people with diabetes and prediabetes, however, this normal process becomes dysregulated. Either the body doesn’t produce enough insulin to rebalance blood sugar levels or it does not respond to the insulin produced. Blood sugar levels therefore continue to rise during fasting. When compared to non-diabetics, therefore, persons with diabetes or prediabetes will have a significantly higher blood glucose content when fasting. In a normal day, this translates to abnormally elevated blood glucose in the morning.

The assessment of fasting blood glucose offers an easy and quick view into how the body manages blood sugar levels. It may also be less variable than other tests, as these are taken sooner after meals and depend more heavily on what was eaten, activity levels and other factors. Despite this, the levels of fasting blood glucose do vary, and will be dependent on a number of factors, including the contents, size and time of the last meal, how the body responds to blood sugar variations and the person’s individual metabolic rate, amongst others. For formal diagnosis, therefore, abnormal blood sugar levels need to be observed on at least two separate occasions.

How is fasting blood glucose tested?

Fasting blood glucose can be tested by obtaining a small blood sample through a simple finger prick in a pharmacy or even at home. This basic assessment will give you an indication of your blood sugar levels. Accurate diagnosis, however, requires a proper blood test. After obtaining a blood sample, it will be sent away for analysis. Ideally, it is best to measure fasting blood glucose in the morning, as you will be in a natural fasting state after not eating since dinner the night before. Testing later in the day is not standard due to day time fasting not being normal, and the discomfort this may cause due to not eating during the day.

What do the numbers mean?

It is important to keep in mind that conclusions can only be made from the average result of at least two tests on different occasions. Blood sugar levels can fluctuate naturally, and a high reading once may not necessarily point to any underlying condition. Furthermore, blood sugar targets are depicted as ranges as there is no one blood sugar level that is ideal in every individual or at every time. As such, your own blood sugar level should be compared to these ranges and then, together with your doctor, interpreted in the context of your own body type, metabolic demands and lifestyle before a definite conclusion can be reached.

In areas outside the USA, including South Africa, blood glucose concentration is measured in millimole glucose per litre of blood (mmol/L). Typically, fasting blood sugar ranges are classified as follows:

  • 3.8 mmol/L or less: Generally too low. Ingest sugar and seek medical attention if symptoms persist
  • From 3.9 to 5.5 mmol/L: Normal fasting glucose levels, ruling out diabetes
  • From 5.6 to 6.9 mmol/L: Impaired fasting glucose, indicating prediabetes and future risk of diabetes. Adopt a healthy lifestyle and seek medical advice.
  • 7.0 mmol/L and above: Diabetes. Seek medical advice and adopt a healthy lifestyle.

How can I reduce my fasting blood sugar?

Apart from medication recommended by your doctor, it is vital to follow a healthy lifestyle if you are to prevent short-term spikes in blood sugar, and, more importantly, stabilize or reverse long-term negative effects of high-blood sugar and diabetes. Adopting a healthy lifestyle and following the tips below can also prevent blood sugar metabolism problems from developing in the first place. Take action today, even if your blood sugar levels are normal.

A healthier blood sugar level can be achieved by:

  • Eating a diet high in plant based foods
  • Avoiding processed foods
  • Avoiding sweets and foods high in sugar. This may include limiting natural sources of sugar such as fruit.
  • Where carbohydrates are included, ensuring they are whole-grain and high in fibre
  • Focussing on high protein foods
  • Eating regular meals
  • Limiting alcohol
  • Getting regular exercise
  • Managing stress
  • Getting regular and adequate amounts of sleep

MNI places emphasis on assisting you with living a better lifestyle and therefore we developed lifestyle support tools:

  • For more information on how to follow a healthy diet, download our free C.A.P.E Meal Plan (your insulin-friendly meal plan) here.
  • You can also begin exercising by adopting one of our exercise plans. Download your free copy here.
  • For further assistance, try our range of products include unique blends of ingredients that work synergistically together to help improve your health outcome. Read more here.