CARBOHYDRATE CONSUMPTION, OVERWEIGHT, OBESITY AND TYPE 2 DIABETES RATES IN AUSTRALIA

In this month’s PERSPECTIVES, we discuss decreasing available carbohydrate consumption in Australia over the past 3 decades, including from sugars. Around the globe, many people believe that excess and increasing consumption of carbohydrate, and in particular free or added sugars, is driving increasing rates of overweight, obesity and type 2 diabetes. As will be demonstrated, the Australian data challenge this line of thought.

Regular GI News readers are well aware that sugars are just one form of available carbohydrate, with the other two major types being starches and maltodextrins. All 3 major types affect blood glucose levels, with differing effects best described by their glycemic index (GI) and glycemic load (GL), not their physical structure.

Total, free and added sugars

Total sugars include those found in healthy foods like fruits, vegetables, milk and yoghurt. What about free or added sugars, which are often refined and may contain fewer beneficial nutrients like dietary fibre, vitamins or minerals?

The World Health Organization (WHO) defines free sugars as all the added sugars put into foods during their processing or preparation as well as the sugars that are naturally present in fruit and vegetable juice, syrups and honey. Sugar naturally present in unrefined foods, such as whole fruit or unflavoured milk, is not considered free sugar.

As mentioned in this month’s FOOD FOR THOUGHT and WHAT’S NEW?, the WHO recommends that free sugars should make up less than 10% of an individual’s daily dietary energy (kilojoule/Calorie) intake.

How much free and added sugars are Australians consuming?

In 2023-24, Australians consumed a daily average of 43 g (~10 ½ teaspoons) of free sugars, most of which came from added sugars (38 g (~9 teaspoons)), rather than from juice, syrups or honey. The average proportion of daily energy intake from free sugars:

• was 8.2%, within the WHO recommendation
• was predominantly from discretionary foods (6.2%) compared to non-discretionary (2.0%)
• decreased from 11.0% in 2011–12, with large decreases for people aged between 2–49 years
• was higher for children and young adults aged 5–11 years (9.4%), 12–17 years (10.1%), and 18–29 years (9.8%) than any other age groups
• was similar for males and females (8.3% and 8.1%).

Where were the free and added sugars coming from?

The main food groups contributing to free sugars intake were:

• Soft drinks and flavoured mineral waters (19.8%)
• 100% Fruit and vegetable juices or Fruit and vegetable drinks (9.0% combined)
• Sugar, honey and syrups (8.2%)
• Sweet biscuits (7.9%)
• Cakes, muffins, scones, cake-type desserts (6.4%).

What about sugar sweetened beverages and their replacements – artificially sweetened beverages?

As discussed in this month’s FOOD FOR THOUGHT, the proportion of people who consumed sweetened beverages has decreased in Australia over time, from 49.2% of the population in 1995 to 28.9% in 2023-4. The proportion of people who consumed:

• sugar-sweetened beverages decreased from 43.2% to 20.9%
• intense (“artificial”) sweetened beverages remained essentially stable (8.4% and 9.6%).

The average daily consumption of sweetened beverages was 159 mL (5.4 Fl ounces), which included:

• 109 mL (3.7 Fl ounces) of sugar-sweetened beverages
• 49 mL (1.7 Fl ounces) of intense-sweetened beverages.

The most popular kinds of sweetened beverages were:

• soft drinks and flavoured mineral waters (23.8%)
• cordials (3.4%)
• energy drinks (1.9%)
• electrolyte drinks (1.2%)
• fruit and vegetable drinks (1.1%).

Are Australians losing weight?

The most recently available prevalence data for Australia were published in 2022, where:

• 26% ( 1 out of 4) of children and adolescents aged 2–17 were living with overweight or obesity.
• 66% (2 out of 3) of adults aged 18 and over were living with overweight or obesity.

The proportion of children and adolescents aged 5–17 living with overweight or obesity increased from 20% in 1995, to 25% in 2017–18 and 28% in 2022.

The proportion of adults aged 18 and over living with overweight or obesity has increased by 10 percentage points, from 56% in 1995, mainly driven by an increase in people living with obesity (from 19% in 1995 to 32% in 2022).

What’s happening with rates of type 2 diabetes in Australia?

Based on the best available data, the total number of people living with type 2 diabetes (i.e., the prevalence rate) in Australia increased almost 3-fold between 2000 and 2021, from around 400,000 (0.4 million) to almost 1.2 million.

It’s not all bad news, however. There has been a steady decline in the age-standardised incidence rate for type 2 diabetes (i.e., new cases of type 2 diabetes) in Australia between 2000 and 2021, with an overall drop of 43%.

Therefore, part of the reason for the increasing total number of people living with type 2 diabetes in Australia is due to the fact that they are living for longer, most likely due to better blood glucose monitoring technology, blood glucose lowering medications, improved diet and overall improved medical care.

In summary, Australian’s have decreased the amount of available carbohydrate, total, free and added sugars in their diets, in particular from sugary drinks, since 1995. Rates of overweight, obesity and type 2 diabetes have continued to rise over the same time frame. Rather than focusing on single ingredients or nutrients, focusing on improving the quality (i.e., glycemic index) of all available carbohydrates and therefore the dietary glycemic load may be a more productive public health strategy for the nation going forward.

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