What are the best sweeteners for people living with diabetes?

There is a lot of controversy regarding  sweeteners (sugar substitutes) and which is better for people living with diabetes. Retha Harmse simplifies the facts.

Sugar consumption

The dangers of excessive consumption of sugar is well-documented. Including how it negatively affects the health status of individuals but even more so for people living with diabetes.

The typical South African consumes 24 teaspoons of sugar daily. More than double of the World Health Organization guidelines for daily intake. Added to that, 7% of the South African population has diabetes (3,85 million people, aged between 21 – 79 years old).

In 1985, 30 million people had diabetes. Its prevalence has increased six-fold and today  425 million people worldwide are currently. If nothing is done now to prevent this, this number will continue to increase to 629 million people by 2045.

Sugars that increase blood glucose levels

Some foods will be labelled “no added sugar” but will still be high in natural sugar (e.g. fruit sugars). These natural sugars also raise blood glucose levels and should be monitored for people with insulin resistance and diabetes.

Sugar Forms & uses Other things you should know
  • Brown sugar
  • Maltodextrins
  • Icing sugar
  • Agave syrup
  • Invert sugar
  • Brown rice syrup
  • White sugar
  • Corn syrup
  • Dextrose
  • High fructose corn syrup
  • Fructose
  • Maple syrup
  • Glucose
  • Fruit juice concentrates
  • Lactose
  • Honey
  •  Maltose
  • Molasses
  • Sucrose
  • Barley malt
  • Used to sweeten foods and beverages.
  • May be found in certain medications.
  • There is no advantage to those with diabetes in using one type of sugar over another (in other words, one teaspoon of sugar has the equal effect of one teaspoon of honey).
  • Sugars may be eaten in moderation. Up to 5% of the daily caloric requirement can come from added sugar.
  • High-sugar diets are not recommended, since such foods could replace more nutritious foods and lead to deficiencies.

Sugars that don’t affect blood glucose levels

Non-nutritive sweeteners, such as aspartame, sucralose, saccharine, stevia, xylitol, and neotame, are so popular due to it being approximately 300 to 13 000 times sweeter than sugar. Though, they don’t have any nutritional value (meaning no or low kilojoules).

Although artificial sweeteners may help to reduce total energy intake, the effectiveness in weight loss or diabetes management has not yet been established. We think fewer calories consumed equals less weight gained or more weight lost, right?

However, according to a recent review, regular consumption of non-nutritive sweeteners is related to an increase in BMI. This might be explained by sweeteners being associated with an amplifying of general cravings and appetite.

Despite this, and this is imperative: sweeteners are not all the same. They have different biochemical structures, with different routes of metabolisation and absorption. Certain sweeteners metabolise differently and are therefore better than others in maintaining blood glucose and weight management. Let’s look at a few different sweeteners and how they weigh up.


Sucralose (sold as Splenda) is 600 times sweeter than normal sugar. It’s mostly secreted which means it does not get absorbed in the body.

Although this might sound great, don’t be so quick to jump on the bandwagon. Sucralose has been associated with inflammation, and there is still ongoing research on whether it increases blood glucose level. The data is leaning towards a ‘no’ for people living with diabetes, as long-term use can cause insulin resistance.

It’s also worth mentioning that added table sugar, if consumed in excess, also causes inflammation and has also been associated with insulin resistance.

Conclusion: Consuming sucralose (or normal sugar) in excess over a long period of time has been linked to inflammation. Sucralose should rather be avoided if you’re diagnosed with any inflammatory diseases such, as rheumatoid arthritis or Crohn’s disease, as it can worsen the inflammatory state.


Aspartame is mostly used in sugar-free or low-sugar drinks and Iced Tea lite.

After the big media frenzy of aspartame causing cancer, recent human studies proved aspartame had no carcinogenic effect. However, it’s worthwhile to note that it’s still not beneficial for your health. More specifically gut health, as aspartame increases certain bacteria in your gut that are directly associated with weight gain.

Furthermore, the long-term (more than 10 years) use of aspartame has been negatively associated with cardiac health. Lastly, aspartame also leads to an increase in carbohydrate cravings, which can lead to increased appetite.

Conclusion: Although aspartame was set-free from being cancer causing, it still increases carbohydrate cravings and the effect it has on gut- and cardiac health shouldn’t be neglected.

Remember that moderation is key. Try to replace diet drinks with infused water or homemade iced teas (rooibos is such a good option). But if you still plan to consume aspartame, be sure to include extra fibrous vegetables, or even a probiotic, to keep the microbiota in balance.

Stevia, erythritol and xylitol

These three sweeteners have been categorised as natural sweeteners. The benefits of these sweeteners are that they don’t need insulin to be metabolised. Therefore, improves glucose tolerance and reduces insulin levels.

Stevia does have an undesirable bitter aftertaste, and erythritol and xylitol are quite expensive (roughly R150-160p/kg). But it seems worth it, because when consuming these natural sweeteners, the rewards system is activated leaving you feeling satisfied. And, in contrast to the previous mentioned sweeteners, they do not increase cravings.

Conclusion: Stevia, erythritol, and xylitol are superior. They can improve glucose levels and aid in weight management, in comparison to the other artificial sweeteners.

Still, moderation remains a key factor in any healthy diet. Therefore, using it sparingly will benefit your health as well as your wallet.

Retha Harmse is a Registered Dietitian and the ADSA Public relations portfolio holder. She has a passion for informing and equipping the in the field of nutrition. She is currently in private practice in Saxonwold, Houghton and believes that everyone deserves happiness and health and to achieve this she gives practical and individual-specific advice, guidelines and diets.


Retha Harmse (née Booyens) is a registered dietitian and the ADSA public relations portfolio holder. She has a passion for informing and equipping in the field of nutrition. She is currently in private practice in Saxonwold, Houghton and believes that everyone deserves happiness and health and to achieve this she gives practical and individual-specific advice, guidelines and diets.

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What fruit is best for you?

Dietitian, Donna Van Zyl, explains the considerations for diabetes patients when eating fruit.

There is often concern as to eating ‘sweet fruit’ if you have diabetes. However, this does not mean that you should avoid eating fruit completely.

Fruit can be classified under the macronutrient, known as carbohydrates. Carbohydrates, or fruit, are digested and converted by the body into glucose and therefore should be counted as part of a carb-counting regimen.

What needs to be considered when eating fruit is: the type of fruit and the quantity consumed as both these influence blood glucose control.

If we look at the type, fruits are classified according to their glycaemic index, which will further have an impact on the spike of the blood glucose level.

Type of fruit: The glycaemic index

What is the glycaemic index (GI)?

It is a numerical measure of the rate i.e. how fast and to what extent the intake of carbohydrate rich foods may affect your blood glucose levels. An item of food with a high GI raises blood glucose levels more than an item of food with a medium or low GI.

Glucose has been given a numerical value of 100, because it is absorbed immediately into the bloodstream. All carbohydrate-containing food, such as fruit, are compared to the reference of glucose.

The low-GI index food items fall below the reference range of 40 (<40) and are given the green to go. Whereas intermediate-GI food items falls within the reference range of 56 – 69; the orange for slow down and proceed with caution. The high-GI food items, with a reference range of above 70 (70+), gets the red for halt.

Though, high-GI fruits can be consumed with exercise, depending on blood glucose levels, and in combination with other foods products, especially protein or fat, or even to correct a hypoglycaemic event.

The GI Foundation uses the following icons to indicate the GI of foods:

Absorption and digestion factors

Factors affecting the absorption and digestion of fruit, which in turn may influence the GI of foods include:

  • The amount of cooking (cooked apple versus raw apple).
  • Processing (fruit versus fruit juice).
  • Ripeness and storage time: the riper a fruit, the higher the GI.
  • The type of fibre (soluble – citrus fruits).
  • The more acidic a food is, the lower the GI value. e.g. lemon juice lowers the GI of the food or meal.
  • The presence of fat, protein or low-GI foods consumed with the GI carbohydrate.

When eating a higher GI fruit, you can combine it with other low GI foods, or protein and fat to balance out the effect on blood glucose levels. For example, eating a fruit salad and yoghurt (plain).

The GI of fruit commonly eaten

Fruit GLYCEMIC INDEX (glucose=100)  Serving size in gram
Apple, average 39 120
Banana, ripe 62 120
Grapefruit 25 120
Grapes, average 59 120
Orange, average 40 120
Peach, average 42 120
Peach, canned in light syrup 40 120
Pear, average 38 120
Prunes, pitted 29 60
Raisins 64 60
Strawberries/Berries 40 120/125
Watermelon 72 120

When looking at the GI of specific fruits above, a variety of low GI fruit should form part of a balanced dietary intake. Fruits are not only delicious, but a good source of fibre which helps aid in regulating blood glucose levels. Fruits are also a good source vitamins, minerals or phytochemicals which aid bodily functions and help fight against disease.

Give preference to apples, berries, peaches or citrus throughout the day and consume with meals to ensure that the rise in blood glucose is covered by the insulin injected i.e. part of carb-counting.

Whereas your high-GI fruit, such as watermelon or grapes, can be used to prevent hypoglycaemia, especially after exercise, or to correct a hypoglycaemic event.


Be mindful of your portions too. You will see the above-mentioned GI of fruit is indicated per quantity. Remember, the more fruit you eat at once, the more fruit sugar is also consumed which will affect blood glucose control.

One small apple provides approximately 15g of glycaemic carbohydrates. So, eating two apples in one go will naturally provide you with up to 30g of glycaemic carbohydrates, which will lead to a spike in blood glucose levels due to quantity consumed.

Take home message

Fruits form part of a healthy balanced intake. A variety of low-GI fruit should ideally be consumed and distributed throughout the day. Be cautious with high-GI fruits, however. they can be useful especially in picking up blood glucose levels.


Donna van Zyl is a private practicing dietitian for Nutritional Solutions, Bloemfontein. She is growing in the field of paediatrics and plays a key role in individualising nutritional therapy for Type 1 diabetics. Her special interest is in optimising health, managing chronic lifestyle related diseases, and sports nutrition. She lectures part-time at the University of the Free State, which she enjoys thoroughly.