Does sugar deserve all the negative publicity it gets? Can sugar be included in the context of a healthy diet? Nutritionist Bronwen King investigates.
Sugar seems to have become food enemy number one these days and many people have had a go at going ‘sugar free’. Some have even given up fruit in an effort to expunge ‘the enemy’. But is this a sensible path? Do we need to give up all sugar and sugar-containing foods or is there a way to enjoy sweet foods without compromising our health?
What is sugar?
Most of us think of sugar as the white stuff we add to our coffee or baking — the stuff that also comes in castor, icing, brown or raw varieties. Scientifically, however, sugar includes all monosaccharides and disaccharides. Monosaccharides have one sugar molecule and include glucose, galactose (found in milk) and fructose (found in fruit) while disaccharides have two monosaccharides bonded together. The most common disaccharide is sucrose, which has become synonymous with table sugar and is a molecule of glucose bonded to a molecule of fructose.
The World Health Organization (WHO) defines sugar further into free sugars and intrinsic sugars:
Free sugars refer to all monosaccharides and disaccharides added to foods by the manufacturer, cook or consumer, plus the sugars that are naturally present in honey, syrups and fruit juice. In other words, all added sugar plus any found naturally in a syrup or extract.
According to this definition, fruit juice with ‘no added sugar’ is no different to ‘fruit juice with added sugar’ in that they are both solutions full of free sugars. Surprising as it may be to some, our bodies do not differentiate between the sugar naturally found in the juice and any that may have been added: they behave and are treated just the same.
Intrinsic sugars are the sugars found in whole fruit and vegetables. The WHO says these sugars are encapsulated by a plant cell wall. These sugars tend to be digested more slowly because the cell wall must be broken down first. They take longer to enter the blood stream than free sugars so are less likely to cause blood sugar spikes.
Why choose intrinsic sugars?
Vegetables and fruit (both containing intrinsic sugars) should not be restricted as they look after our health and weight in many ways:
- Their slow digestion means better blood sugar control and less requirement for insulin and since insulin encourages fat storage, less likelihood of weight gain.
- They contain valuable vitamins, minerals and antioxidants.
- They are mostly water, and since water bound this way fills us up, they are very filling for the kilojoules they provide — another plus for weight management.
- They do not promote tooth decay like free sugars do.
It is important to note that dietitians and nutritionists recommend limiting cooked starchy vegetables (potatoes, kumara, taro etc.) to one-quarter of our dinner plate. This is because starch turns quickly to glucose (which is quickly absorbed) and peeling and cooking starchy vegetables speeds up this process.
Why limit free sugars?
The WHO suggests we limit free sugars because of the evidence of their impact on our health, specifically on weight gain and dental health. So before we have a free-for-all on low-sugar muffins and sugar-free chocolate, keep that in mind. If we’re still consuming excess kilojoules we defeat the purpose of limiting free sugars. And remember: diet sodas are still acidic on our teeth, so we don’t want to overdo those either.
Do I have to quit all free sugars?
Most scientists, dietitians and nutritionists would agree that too much free sugar has the potential to harm our health but small amounts used cleverly should not be a problem. The WHO suggests we limit free sugars to no more than five per cent of energy (kJ): this means a day limited to six teaspoons of free sugars for adults and three teaspoons of free sugars for children. Given that a standard 600ml fizzy drink has around 16 teaspoons of sugar, this may be a big ask for many Kiwis!
What about milk sugars?
Milk and dairy products do contain natural sugars but these don’t count as free sugars as they don’t have the same detrimental impacts on our health.
Don’t be fooled by sugar claims
Claim: 100% natural sugar
This is a confusing claim since all sugars as identified by FSANZ (Food Standards Australia and New Zealand) are natural in that they are plant extracts. Sugar as defined by FSANZ includes white sugar, castor sugar, loaf sugar, cube sugar, icing sugar, coffee sugar, coffee crystals or raw sugar. People commonly applaud fruit juice because its sugars are ‘natural’ not considering that sugar from sugar cane or beets is just as natural! This claim could be used to differentiate sugar (sucrose) from artificial sweeteners — even so, it is a marketing tool rather than a source of useful information.
Claim: No added sugar / refined sugar free
This means none of the sugars listed in the FSANZ definition of sugar have been added. It does not mean there is no sugar naturally occurring in the product (as with fruit juice).
Claim: No added cane sugar
This means the same as no-added sugar, since all of the sugars included in the FSANZ definition of sugar come from sugar cane. Sugar can also come from sugar beets. This does not mean the product has no sugar.
This means the product contains none of the sugars listed in the FSANZ definition of sugar. The term is commonly used in products that have added artificial sweeteners instead, for example, sugar-free gum. It could mean food is sweetened with dried fruit or honey so make sure to check the ingredients.
Claim: 50% less sugar
This means 50 per cent less sugar (as defined by FSANZ) than a standard product. Just Juice, for example, has a juice with 50 per cent reduced sugar which is sweetened by stevia. Since this claim would only be used with a normally high-sugar product, it does not necessarily mean the product is low in sugar.
The easiest way to identify sugars on labels is to look for words that end in ‘-ose’. Common varieties are glucose, fructose, maltose, lactose and sucrose. Other ingredients that mean sugar include honey, golden syrup, maple syrup, corn syrup, treacle, molasses and high fructose corn syrup. Since ingredients list different sugars separately you need to add them up to get an idea of how much sugar is in a product. For example, a label that included corn syrup, honey and molasses in the first few ingredients would be very high in sugar.
30 names for sugar in our food
- Agave nectar
- Beet sugar
- Blackstrap molasses
- Brown sugar
- Cane sugar
- Coconut sugar
- Confectioner’s sugar
- Corn syrup
- Demerara sugar
- Fruit juice
- Fruit juice concentrate
- Golden syrup
- High fructose corn syrup
- Icing sugar
- Invert sugar
- Maple syrup
- Palm sugar
- Raw sugar
- Rice syrup
Myth: Sugar only adds sweetness
Yes, it provides kilojoules with no nutritional value. But sugar has useful functions beyond just taste. Sugar is a natural preservative and essential for preserving jams, jellies, chutneys and relishes. It is a key ingredient in baked goods as it tenderises gluten (the structural component of cakes and biscuits) to create a soft, melt in the mouth crumb and it caramelises to create a crisp texture and golden colour. It is essential in bread-making and alcohol production as it provides food for the yeast.
Myth: Sugar causes hyperactivity
Perhaps surprisingly for parents, the science doesn’t support this. Sugary food is commonly consumed at celebrations when lots of other things are going on to get kids excited. In one study five parents who were told their children had consumed sugar were more likely to classify the child’s behaviour as ‘hyper’ when in fact none of the children in the study had been given sugar.
Myth: It is the sugar in alcohol that is making me fat
It is actually the alcohol component of drinks (at 27 kilojoules per gram compared to 17 kilojoules per gram for sugar) that puts on the beef.
Alcohol is produced when sugar is converted through fermentation to alcohol and carbon dioxide. Since there is no mandatory nutrition labelling of alcoholic beverages in some parts of the world it is difficult to determine exactly how much sugar is present but since most of it is converted to alcohol, sugar is not a significant source of kilojoules/calories.
Myth: Sugar causes diabetes
If you have type 1 or type 2 diabetes you definitely need to monitor your sugar and carbohydrate intake in order to manage blood sugar levels. If you don’t have diabetes, however, sugar intake alone won’t cause you to develop it. The main risk factors for type 2 diabetes are being overweight, inactivity and a diet high in overall kilojoules.
Myth: Brown sugar is better for you than white sugar
Brown sugar is just white sugar with molasses added back in. You would have to eat a massive amount of brown sugar each day to take advantage of the tiny amounts of minerals the molasses delivers, and the negatives of this would greatly outweigh any potential advantage.
Myth: Eating too much fruit is bad
Yes, fruit contains sugar but since it is intrinsic sugar it does not compromise health. Also, the amount it contains is small compared with the filling power it delivers — compare the filling power of four oranges compared to the juice these would provide (a medium-sized glass-full). And fruit is a vital source of fibre, vitamins, antioxidants and anti-inflammatory compounds that help protect us against disease. Eating fruit is a valuable part of a healthy diet — aim for two serves every day.
How to have a low-sugar day
The WHO recommends we get no more than five per cent of our energy from free sugars. So in an average 8700kJ day, that would be no more than 26g. It’s not easy to calculate this though, so we’ve done it for you. Our menu plan (see Downloads at the end of this story) sees every day below the recommended five per cent threshold. Saturday, for example (below), has 19.1g free sugars, which provides 325kJ, or 3.7 per cent of the 8850kJ day.
|Breakfast||Cinnamon and banana pikelets with sliced banana, 1/2 cup blueberries, reduced-fat Greek yoghurt and sliced almonds||The pikelets contain nearly 9g free sugars per serve. We use yoghurt without added sugar.|
|Snack||Peanut butter brownie
Cup of tea
|The peanut butter brownie adds around 8.5g free sugars. We don’t add sugar to tea or coffee.|
|Lunch||Kumara, capsicum and wild rice salad with orange dressing
100g grilled chicken, sliced
|The orange juice in our dressing adds nearly 2g free sugars.|
|Snack||1/2 serve Corn, prawn and courgette fritters||Our veges are sweet enough — no free sugars here. Again, we use unsweetened yoghurt.|
|Dinner||Quick salmon and lemon pasta
Small bowl of grapes
|No added sugars or juice in our dinner.|
You can see it’s possible to stay below five per cent free sugars. But the amount of free sugars in a day can skyrocket quickly if we’re not careful.
By adding 1/2 glass of juice and an Apricot and goji berry bar to Saturday, you would consume 40.5g free sugars, and 1000 extra kilojoules (seven per cent free sugars)!
Checklist: How to consume sugar wisely
- First (and greatest) priority: minimise sugary drinks and confectionery. These provide kilojoules with no nutritional goodness and in large quantities have the potential to harm. If you have sugar in your tea and coffee, gradually wean yourself off it.
- Restrict sugary foods that have no nutritional merit. By this we mean cakes, biscuits and pastries that are made from sugar, white flour and fat. Often these foods are just habit, and can be replaced successfully with more nutritious sweet foods.
- Use fruit as a source of sweetness on cereals, in desserts and in baked goods. Leave skin on fruit where possible to increase fibre content.
- Include other high-fibre ingredients in baked goods and desserts. Wholemeal flour, grated vegetables, nuts, seeds and dried fruit will all slow down digestion and result in better blood sugar control.
- Don’t stress if you need a little sugar/jam/honey on cereal or toast. Just make sure what you are having it with is high in fibre as this will help slow down digestion and absorption into the bloodstream.
See our feature How to stop sugar cravings for more handy tips.
What about sugar alternatives?
New products such as stevia, agave and coconut sugar are commonly seen on retail shelves and in recipes. Are we just fooling ourselves when we substitute these for regular sugar (sucrose) or is there some merit in doing so?
Stevia is a natural sweetener which comes from a South American plant, has been around for centuries and is considered safe. Its advantage lies in the fact that it has zero kilojoules and does not raise blood sugar, but some people find it has a metallic aftertaste.
Agave comes from the blue agave plant (which is also used to make tequila). Like sucrose,it is composed of glucose and fructose but is higher in fructose than sucrose (which is 50 per cent fructose). Since the body does not recognise where molecules of glucose and fructose have come from be it sucrose or agave, the same advice applies to this as to sugar. Also, since agave delivers more kilojoules per unit weight than sucrose, there is no kilojoule advantage to be had by using it.
Artificial sweeteners: Whatever the variety, these still reinforce a sweet taste and do nothing to reduce a ‘sugar habit’. Recent studies on mice suggest artificial sweeteners may also induce glucose intolerance and therefore increase the risk of type 2 diabetes by altering the gut microbiota.
Honey is often used as a sugar substitute because it has healthier connotations. Honey has a slightly different mix of glucose and fructose than regular table sugar (sucrose) and also contains varying amounts of minerals such as zinc and selenium. Honey is mostly sugar: it may be a slightly better choice but as with anything sweet, don’t overdo it.
Coconut sugar: Anything ‘coconut’ seems to be wearing the popularity crown at the moment. Like sucrose, however, it is still composed of glucose and fructose. A recent study in the ASEAN food journal found that coconut sugar is 78 per cent sucrose (compared with 100 per cent of table sugar). The other 22 per cent is made up of inulin (a type of fibre that supports gut health) and antioxidants. This gives it a lower glycaemic index than table sugar, something which proponents have latched onto. However, since it is a free sugar (taken out of the cells that would naturally contain it), limited use is advised. Think of it as you would honey — a slightly better alternative to sugar but still something to limit.
Sugar alternatives and artificial sweeteners all reinforce a sweet tooth. Instead of searching high and wide for the perfect no-kilojoule sugar replacement it seems smarter to eat sugar the ‘old- fashioned’ way: ie. ‘less is best’ (see Checklist: How to consume sugar wisely, above). Skip the soft drinks, juice, cakes, bikkies, lollies and all too sweet yoghurts and just add a little sugar to real foods occasionally when needed. If a little sugar sprinkled on porridge is enough to induce a child to eat oats, then this is a no-brainer.
Article sources and references
- Digitale E. 2012. Debunking a Halloween Myth: Sugar and hyperactivity. Published by Stanford Medicine. http:// scopeblog.stanford.edu/2012/10/31/ debunking-a-halloween-myth-sugarand- hyperactivity/http://scopeblog.stanford.edu/2012/10/31/debunking-a-halloween-myth-sugar-and-hyperactivity/
- FSANZ. 2013. Ingredient Labelling of Foods. User guide to Standard 1.2.4 — Labelling of ingredients. http://www. foodstandards.govt.nz/code/userguide/ pages/ingredientlabelling.aspxhttps://www.foodstandards.gov.au/code/userguide/Documents/Guide%20to%20Standard%201.2.10%20-%20Percentage%20Labelling%20of%20Food.pdf
- Hoover DW & Milich R. 1994. Effects of sugar ingestion expectancies on mother-child interactions. Journal of Abnormal Child Psychology 22:501-15https://www.ncbi.nlm.nih.gov/pubmed/7963081
- Purnomo, H. 1992. Sugar components of coconut sugar in Indonesia. ASEAN Food Journal 1992 7:200-1https://www.academia.edu/21090889/Sugar_components_of_coconut_sugar_in_Indonesia
- Suez J et al. 2014. Artificial sweeteners induce glucose intolerance by altering the gut microbiota. Nature 514:181-6https://www.ncbi.nlm.nih.gov/pubmed/25231862
- Wolraich ML et al.1995. The effect of sugar on behavior or cognition in children. A meta-analysis. JAMA 274:1617-21https://www.ncbi.nlm.nih.gov/pubmed/7474248
- World Health Organisation. 2013. Bulletin of the World Health Organisation 92:780-1 www.who.int/ bulletin/volumes/92/11/14-031114.pdfhttps://www.who.int/