The claim

Alison Watkins, the group managing director of Coca-Cola Amatil, has argued against a sugar tax, emphasising that despite a fall in the consumption of added sugars since 1995, obesity rates have continued to rise.

A sugar tax, therefore, would not reduce obesity in Australia, she wrote in an opinion article published in The Australian in May. The answer, instead, lay in a mix of diet and physical activity, she argued, yet the public debate was focused on diet.

In mounting her case, Ms Watkins implied there was an inverse causal relationship between sugar consumption and obesity.



"Sugar consumption is down but obesity is up," she wrote.

"It's the same in the US: obesity has more than doubled since 1990 while sugar intake fell. Clearly, neither sugar, nor drinks sweetened with sugar, were the major cause of this obesity rise."

Noting that "just 2 per cent of the average Australian's kilojoule intake comes from soft drinks", she drew her argument to a close, saying there was little evidence that sugar taxes worked and that a tax, if introduced in Australia, would likely generate "little or no return in obesity reduction."

Is sugar consumption down? And have obesity rates in Australia risen regardless? RMIT ABC Fact Check investigates.

The verdict

Ms Watkins's claim is spin.

Yes, the consumption of added sugar, particularly of carbonated drinks, has fallen since the mid-1990s. Meanwhile, obesity rates have indeed continued to rise. But this is not the full story.

In attempting to put the case against a sugar tax, Ms Watkins paints an incomplete picture of the link between sugar-sweetened beverages and obesity, ignoring the weight of scientific evidence.

Authoritative research shows a consistent association between a high intake of sugar-sweetened beverages and obesity. Indeed, research shows that adolescent boys, who are the biggest consumers of sugar-sweetened drinks, also have the fastest rates of weight gain.

Sugar and obesity — what's the real story? ( ABC Far North: Mark Rigby )

Ms Watkins refers to the fact that just 2 per cent of the average Australian's kilojoule intake comes from soft drinks.

But "soft drinks" refers only to carbonated drinks, not the full gamut of available sugar-sweetened beverages, including sports drinks, iced teas and fruit juices.

Anna Peeters, an expert in obesity and nutrition at Deakin University, told Fact Check that to be able to explain divergent trends in sugar consumption and obesity rates it was necessary to consider consumption patterns among groups of people, as well as the population as a whole.

This was because overall averages could mask increased consumption of sugary drinks among a particular group, which could be underpinning a rise in obesity.

In her article, Ms Watkins also refers to an Australian Bureau of Statistics analysis showing a relative decrease in the consumption of added sugars in people's diets between 1995 and 2011-12, but she does not mention significant caveats the ABS attached to its analysis.

Nor does she mention that despite the decline, annual sales of soft drinks increased substantially over the 50 years to 1999, or that market research shows total sales of sugar-sweetened beverages continue to grow, albeit at a slower rate.

Also, she does not mention that Australia's consumption of sugary drinks per capita exceeds the World Health Organisation's recommended energy intake from sugars.

The connection between sugar consumption and obesity

The primary drivers of excess weight gain and the relative importance of dietary factors in obesity remain contentious.

However, there is increasing concern that the consumption of added sugars, especially in the form of sugary drinks, can lead to weight gain, as well as an increased risk of type 2 diabetes and cardiovascular disease.

This has led to the introduction of sugar taxes in nearly 30 countries and there have been calls from public health advocates for Australia to follow suit.

While there are noted deficiencies in the statistics available on food supply and sugar consumption in Australia, many studies have shown a strong association between sugar intake and weight gain.

A 2013 study commissioned by the World Health Organisation and published in the British Medical Journal found a "clear positive association" between high intake of sugars and body fatness. The study involved an exhaustive analysis of available evidence.

Another study, which systematically reviewed evidence from 2013 to 2015, came to the same conclusion.

A third study reported that cumulative evidence from trials and studies was "sufficient to conclude that regular consumption of sugar-sweetened beverages causes excess weight gain and these beverages are unique dietary contributors to obesity and type 2 diabetes."

As far as Fact Check was able to establish, none of these studies was funded by the sweetened beverages industry and the authors of all three papers reported no conflicts of interest.

Kathryn Backholer, a senior research fellow with the Global Obesity Centre at Deakin University, told Fact Check that all three studies constituted reputable and reliable research conducted by academics renowned in their field of expertise.

How fat are Australians?

In 2014-15, 63 per cent (almost two-thirds) of Australians were overweight or obese, with more men being fatter (71 per cent) than women (56 per cent).

Twenty years earlier, 57 per cent of Australian adults were overweight or obese.

Among children and adolescents aged 5–17, the rate of overweight and obesity was 27 per cent, up from 21 per cent in 1995.

Children 10–17 were significantly more likely to be overweight and obese than their counterparts 20 years earlier.

Percentages of obese and overweight adults

Overweight and obesity are measured by the body mass index (BMI), an index of weight-for-height. For adults, the WHO defines overweight as a BMI of 25 and greater, and obesity as 30-plus.

The Heart Foundation provides a free online tool for calculating a person's BMI.

Is the consumption of added sugar falling?

Fact Check asked Dr Backholer to assess the ABS analysis used by Ms Watkins to argue that sugar consumption has been falling since 1995.

The ABS analysis compared sugar consumption data from surveys conducted in 1995 and in 2011-12. It showed the average proportion of dietary energy from sugar fell from 12.5 per cent in 1995 to 10.9 per cent in 2011-12.

As correctly noted by Ms Watkins, the decline was driven by a 6 per cent drop for adults and a 23 per cent drop for children.

Free sugar energy intake of children



But the ABS listed key caveats, including that differences in food coding, classification and methodology, made a true side-by-side comparison between the 1995 survey and the 2011-12 survey impossible.

Rather, the study provides a comparison on a relative basis; that is, a comparison of the proportion of energy from sugar, rather than actual grams of sugar consumed.

Furthermore, the ABS noted a significant under-reporting of the amounts of food eaten by people in both nutrition surveys, particularly the 2011-12 survey.

Ms Watkins does not mention this in her article. She also does not acknowledge two further qualifying points when referring to the ABS analysis.

Firstly, that results from both the 1995 and 2011-12 surveys show soft drinks, energy/electrolyte drinks, cordials, fruit juice and fruit juice drinks are the most common source of added sugars in people's diets — and that diet is a major contributor to obesity.

Second, that sugar consumption exceeded the World Health Organisation's recommended energy intake from sugars. Added sugar consumption may have fallen, but Australians are still consuming far too much.

Dr Backholer said the premise of Ms Watkins' argument was based on ecological research (observational study analysed at population level, rather than individual level), which represented the weakest type of evidence.

Anna Peeters, professor of epidemiology and equity in public health at Deakin University, described Ms Watkins' argument as an "ecological fallacy".

She said "an ecological association would never trump a causal association and we have a number of papers showing a causal association between sugar intake and weight gain."

What is the recommended daily intake of added sugar?

The World Health Organisation recommends adults and children reduce their daily intake of added sugars to less than 10 per cent of their total energy intake.

It says a further reduction to below 5 per cent — about six teaspoons a day — would provide additional health benefits.

One in two Australians (52 per cent) usually exceed the 10 per cent WHO recommendation, according to 2011-12 ABS data from its Australian Health Survey.

In fact, Australians consumed, on average, 60 grams of sugar per day — the equivalent of 14 teaspoons.

Teenage boys (aged 14-18) consumed the most added sugar, averaging 22 teaspoons a day, while the top 10 per cent of male teenagers consumed at least 38 teaspoons a day.

Teenage boys

Australians are big consumers of sugar-sweetened beverages, according to the Australian National Preventative Health Agency.

Indeed, Australia is among the top 10 nations in the world for per capita consumption of sugary drinks, with 1.6 billion litres sold in 2011.

Consumption levels have increased dramatically over the past five decades and remain high, although there are signs that consumption may be levelling off or declining slightly.

Beverage industry sales data shows that between 1997 and 2011 sales of sugary drinks rose 5 per cent, largely due to increases in sales of energy drinks, iced teas and sports drinks.

Simultaneously, Australians shifted away from fizzy drinks, sales of which were down 11 per cent.

Faced with declining sales, Coca-Cola Amatil, one of the biggest bottlers of sugary drinks, is among several beverage companies that have committed to reducing sugar across the industry by an average of 20 per cent by 2025.

Teenage boys as a group have a high level of consumption of sugar. ( ABC Illawarra: Rory McDonald )

In the meantime, although consumption of sugary drinks overall is falling, it continues to rise among adolescent boys.

The ABS survey data revealed that, of those who consumed sweetened beverages the day before being surveyed, the median volume of sugar-sweetened beverages consumed among adults was the equivalent of a regular can (375 ml), with males drinking more than females.

Significantly, for boys aged 14-18, almost a third of their total sugar intake came via sugar-sweetened beverages, with soft drinks and flavoured mineral waters the biggest contributors.



Tim Gill, of the University of Sydney School of Medicine, told Fact Check that while sugar consumption may have fallen in Australia, teenage boys as a group were drinking far too many sugar-sweetened beverages.

"That is the group where we are seeing the fastest rates of weight gain," he said.

Professor Gill, an expert in obesity and nutrition, said weight gain in young children was slowing, especially in NSW, but it continued to increase in older children and adults.



He said NSW data showed that between 2010 and 2015, rates of overweight and obesity did not significantly increase among children in primary school, but did increase significantly among adolescents in secondary school (from 22 per cent in 2010 to 27.4 per cent in 2015).

Percentages of obese and overweight children



Teenage boys and their high consumption of sugary drinks are the nub of the problem. While added sugar consumption may be falling in terms of population averages, it is not falling among sub-groups such as teenage boys, for which obesity rates are rising the fastest.

If sugar consumption is down, why are obesity rates rising?

Deakin University's Professor Peeters said there were several explanations for the "apparent paradox" of declining sugar consumption and rising obesity rates as outlined by Coca-Cola Amatil's Ms Watkins.

If sugar consumption among a healthy sub-group fell, it could represent an overall reduction in sugar consumption.

But if another sub-group was still drinking too many sugary beverages, then obesity rates could continue to rise.

Professor Peeters explained that imbalances in diet and sugar-sweetened beverage consumption were high in Australia.

"The question is what are ... possible reasons for this apparent paradox? One important one is population averages hide a lot of detail.



Have sugar-sweetened beverages contributed to a rise in obesity? ( Wikimedia Commons )

"So, imagine if all the reductions in sugar intake — which is definitely happening for sugary drinks — are by the highly educated, already-healthy weight population. Then we could see both a reduction in population sugar consumption and ongoing increases in obesity in poorer, less educated groups."

She said another explanation was that obese people may be cutting back on their sugar consumption but their weight drop was not sufficient to move them out of the obese category or to counterbalance the number of people still becoming obese.

Sydney University's Professor Gill said Ms Watkins' argument that a sugar tax was pointless given a decline in sugar consumption and rising obesity, was a "fallacious argument", similar to that mounted in a now notorious academic paper titled The Australian Paradox.

This paper, while not specifically about a sugar tax, highlighted diverging trends in sugar consumption and obesity rates. But the paper was discredited after it was found the authors did not consider the effects of imported foods containing sugar.

"The most important argument ... is not whether sugar and soft drinks are the major cause of obesity," said Professor Gill.

"The most important thing is to know that if you reduce your soft drink consumption and if you reduce your intake of sugar, then you reduce your weight."

Principal researcher: Sushi Das

@sushidas1

Sources