There is demand for sugar-free foods, but do the products deliver on their better-for-you promise? We investigate the two largest categories, soft drinks and confectionery.

Background

An Ipsos survey in 2016 found cutting back on sugar came in at number three of the top five food priorities of Australian consumers. Market researchers Frost & Sullivan found people don’t buy sugar-free foods because of health conditions (such as diabetes) but just to eat in a more health-conscious way. Sugar-free products are predicted to grow at a compound annual growth rate of 7% between now and 2021.

Soft drinks

No added sugar or ‘diet’ soft drinks (sodas) are a good example of products where taking the sugar out is relatively easy, although it comes at a cost to flavour. Non-nutritive sweeteners cannot mimic the mouthfeel of sugar and often create a bitter or astringent after-taste.

All of the kilojoules in regular soft drinks are from the sugar, so sugar-free drinks represent a kilojoule saving. However this will only be if those kilojoules are not compensated for elsewhere in the diet.

While low-kilojoule sweeteners have been demonstrated as safe, the use of diet soft drinks and low-kilojoule sweeteners generally has been associated with weight gain and metabolic risk, particularly in animal studies. In humans, RCT evidence does not support a benefit for weight management, and observational data suggest routine intake may be associated with increased BMI and cardiometabolic risk, although this may reflect reverse causality.

One systematic review and meta-analyses in both animals and humans found low-energy sweeteners did lead to reduced energy intake and body weight. The role of non-nutritive sweeteners in weight management remains controversial.

No added sugar soft drinks are still acidic which poses a risk for dental enamel erosion (as do fruit juices).

Sugar free soft drink (vs sugar sweetened soft drink) pros:
reduce/remove kilojoules

Sugar free soft drink (vs sugar sweetened soft drink) cons:
inferior flavour; dental erosion risk from acidity; lack of proven health benefits; possible risk of harm

Confectionery

Sweetness is a big part of the sensory appeal of confectionery yet they are the archetypal ‘sometimes food’. The appeal of sugar-free confectionery is the possibility of pleasure without the guilt; sugar-free confectionery hits the motivational ‘sweet spot’ between risk and reward. However there is more than just sugar in confectionery. Confectionery products vary in their nutritional composition and the health effects of their ingredients.

Sugar free chocolate

Sugar provides a little less than half the kilojoules in chocolate (44%), and fat provides almost all the rest (48%) – the small remainder is from protein. The predominant fat in chocolate is saturated fat, although the fatty acid profile depends on cocoa solids content, and cocoa butter content versus the use of cheaper fats. Sugar-free chocolate is still an energy dense discretionary food. To replace sugar, polydextrose is used as a bulking agent, sugar alcohols (eg maltitol, erythritol) are used for bulk and sweetness, and often an intense low kilojoule sweetener is used as well (eg stevia).

The comparison table below shows the nutritional differences between examples of regular and sugar-free chocolate.

In the dark chocolate example, the kilojoules and saturated fat content differences are negligible. In the milk chocolate example, the saturated fat is similar and the kilojoule saving is only 5%.

The only real difference is the carbohydrate content. A 50g serving of dark chocolate contains one 15g carbohydrate exchange, and the same amount of sugar-free dark chocolate contains half an exchange. It may be tempting to eat twice as much of the sugar-free chocolate for the same carbohydrate value but doing this also doubles kilojoules, and takes saturated fat intake above the Acceptable Range to reduce chronic disease risk (10% kJ, or 24g, in an 8700kJ diet).

Eating 100g may also take an individual above the threshold for a laxative effect. No-added-sugar chocolate is less cariogenic (dental caries causing) than regular chocolate, but regular plain chocolate has a lower acidogenic potential than other lollies (candy) due to its low retentiveness and high saliva response.

Examples of nutritional information in regular vs' no-added-sugar chocolate

Sugar free chocolate (vs. sugar-sweetened) pros:
Reduced carbohydrate content.

Sugar free chocolate (vs. sugar-sweetened) cons:
Negligible kilojoule saving; high in saturated fat; excess consumption may have laxative effect; not suitable on a low FODMAP diet.

Warning: may have laxative effect
Sugar free chocolate and confectionery must carry a warning that excess consumption may have a laxative effect. This is required when sugar alcohols (polyols) or polydextrose are used as ingredients. They have this effect because they are not digested but rather partially fermented in the colon.

FODMAPs

FODMAP is an acronym describing Fermentable Oligosaccharides (galacto-oligosaccharides {GOS} and fructans), Disaccharides (lactose), Monosaccharides (fructose) and Polyols. These short chain carbohydrates present in many no-added-sugar foods can exacerbate symptoms of Irritable Bowel Syndrome (IBS) and people with IBS are advised to avoid polyols in sugar-free foods on a low FODMAP diet.

Sugar free lollies

Traditional lollies are essentially flavoured and coloured sugar, so sugar-free lollies require the use of more bulking sweeteners such as sugar alcohols, or polyols. Lollies also often include glucose which has the highest GI of all carbohydrates, so sugar free lollies offer definite advantages for blood glucose control.

Lollies fall into two main categories, hard and soft. Hard lollies are for sucking over a prolonged period of time and this is a major cariogenic aspect of their consumption when made with sugar because the teeth are coated in fermentable carbohydrate over a longer period. Soft lollies such as jelly beans/babies are chewed and, despite their stickiness, clear the mouth faster. They both elicit a strong saliva response which helps them clear the mouth.

Lollies are bad news for teeth when consumed too frequently so sugar free lollies represent a major dental health advantage because polyols and low-kilojoule sweeteners cannot be utilised by plaque bacteria.

As most of the kilojoules in lollies come from sugar, sugar-free lollies represent a kilojoule saving: 50% in the hard lolly, and 23% in the soft lolly examples below (the difference is due to the higher protein content from gelatine in the soft lolly).

Examples of nutritional information in regular versus zero sugar lollies

Sugar free lollies (vs. sugar sweetened) pros:
Reduced kilojoule content; no dental caries risk.

Sugar free lollies (vs. sugar sweetened) cons:
Excess consumption may have laxative effect, not suitable on a low FODMAP diet.

Sugar free gum

This is another category with oral health benefits. Chewing sugar-free gum after eating reduces the risk of dental caries because it helps to clear the mouth and increase saliva flow which increases the pH and reduces acid attack by plaque bacteria.

The scientific evidence for sugar-free gum reducing caries risk has also been supported by the World Dental Federation, Health Canada and The European Commission (EC). Like sugar-free confectionery, sugar free gum also contains polyols and a warning that excess consumption may have a laxative effect. Sugar free gum is not suitable on a low FODMAP diet.

Sugar free gum (vs sugar-sweetened) pros:
Dental health benefit when chewed after eating.

Sugar free gum (vs sugar-sweetened gum) cons:
Excess consumption may have laxative effect; not suitable on a low FODMAP diet.

People with diabetes

Sugar-free foods used to be a niche food category purchased only by people with diabetes. While sugar-free foods can offer distinct advantages to help avoid significant post-prandial blood glucose increases, diabetes health organisations do not recommend a sugar-free diet. Rather, they recommend a healthy balanced diet high in fibre and choosing low GI carbohydrate rich foods where possible.

Diabetes Australia says,

“A healthy eating plan for diabetes can include some sugar… however foods that are high in added sugars and poor sources of nutrients should be consumed sparingly… foods and drinks that have been sweetened with an alternative sweetener such as… sugar-free lollies etc, are best enjoyed occasionally…”