For many, sugary foods have been staples since childhood. Added sugar sweetens our tea/coffee, dusts our pancakes and, of course, is central to many of the treat foods that we may indulge in.
But what role do sugars have in our diet? How much and of what kind should we eat each day?
What are sugars?
Sugars are a type of carbohydrate found in the foods we consume (the other types are starches and maltodextrins). Some sugars in our food occur naturally, some are added. The source is important. Many foods naturally high in sugar are very nutritious like fruit, milk and yoghurt. Unfortunately, food labels don’t tell you whether the sugar they contain are naturally occurring or added, or help you distinguish between the slowly absorbed and the rapidly absorbed sugars either.
The main types of sugar are the monosaccharides fructose, glucose and galactose, and the disaccharides sucrose (fructose + glucose), maltose (glucose + glucose) and lactose (galactose + glucose).
Fructose is found naturally in fruit and honey. Glucose is found naturally in fruits, some vegetables, and the nectar and sap of plants, and is also added to foods as a sweetener. Galactose is found in milk. Sucrose is the regular table sugar you put in your tea/coffee. Maltose is naturally occurring in beer and bread. Lactose is the sugar that is naturally found in dairy foods like milk and yoghurt. Rice syrup is a mixture of the sugars glucose and maltose.
How do sugars work in the body?
Regardless of the source, sugars work like any other macronutrient in that they get broken down in your digestive tract and are absorbed into your bloodstream. They are then converted into their simplest form, glucose, which is used as energy (the main fuel for our brains and nervous system and our muscles during certain forms of exercise) or stored as glycogen in your liver and muscles, and sometimes as fat, depending on your body's needs.
There is a misconception that all sugars have a high GI. In fact, a lot of foods containing naturally occurring sugar have a low GI e.g., most fresh fruit and dairy foods, and will be absorbed slower into your bloodstream, helping manage your energy levels. Refined added sugars like sucrose have a medium GI. Glucose, maltose and rice syrup all have a high GI.
As for the adverse health effects of added sugar, there’s no doubt that they contribute to dental caries - i.e. tooth decay - in the long term if you don’t brush your teeth regularly, but then so do refined maltodextrins and starches.
Traditionally, sugar has been blamed for causing type 2 diabetes but we now know that it's not that simple. The causes of type 2 diabetes are complex and are not due to one food, ingredient or nutrient alone but likely to be a combination of family history, age, ethnicity, lack of exercise, obesity, and many other factors including a high consumption of high GI foods over the course of a lifetime. Added refined sugars can contribute unwanted kilojoules, which can contribute to weight gain, and some are high GI, which can in turn contribute to the development of type 2 diabetes.
How much sugars?
The Australian Dietary Guidelines don't specify exactly how much - or how little – total or added sugars you should eat. However, they do recommend that people “limit their intake of foods and drinks containing added sugars such as confectionary, sugar-sweetened soft drinks and cordials, fruit drinks, vitamin waters, energy and sports drinks”.
The World Health Organisation (WHO) recommends limiting your daily added sugars intake to no more than 10% of total energy (kilojoule) - which amounts to about 55 grams, or 12 teaspoons each day for the average Australian adult.
Here at the Total Wellbeing Diet we have a more practical take on sugars consumption and we prefer to recommend food groups to single nutrients or ingredients. After all, you eat food and not nutrients or ingredients.
On the Total Wellbeing Diet, we allow 1 indulgence food each day. Typically, that can be a scoop of ice cream, a few squares of chocolate or a small glass of wine.
Do sugars make us gain weight?
Too much of any food will make you gain weight - whether that's chocolate bunnies or chia seeds. The problem for some is that it's easier to over-consume foods high in added sugars than, say, foods that are high in starch and accompanying dietary fibre. That’s where the Australian Dietary Guidelines come in – limit your intake of discretionary foods and drinks containing added sugars, but little else, such as confectionary, sugar-sweetened soft drinks and cordials, fruit drinks, vitamin waters, energy and sports drinks.
Of course, we should also limit our consumption of discretionary foods low in sugars, but high in refined maltodextrins, starches and fats, like potato crisps, extruded savoury snacks and rice crackers. And let’s not forget about limiting those alcoholic drinks that are also discretionary – 1 standard drink a day is enough for those trying to lose weight and keep it off.
According to our own Healthy Diet Score, which has so far been completed by almost 77,000 Australians, our intake of discretionary foods and drinks is three times higher than the recommended daily limit. Blaming the obesity epidemic on sugars alone is therefore too simplistic. It’s a complicated issue that cannot be reduced to a single cause. If it was that easy, it would have been relatively easy to fix.
The bottom line is that when making food choices, you should consider more than the sugars content. It is more important to consider the total amount of carbohydrate, and its GI rating, protein and the overall nutritional quality of a food including the amount of kilojoules, fat, saturated fat, sodium (salt) and fibre.