Two leading nutritionists have quietly made major corrections to a controversial research paper claiming Australians are drinking less soft drinks now than 20 years ago.
The Australian Paradox, written by Professor Jennie Brand-Miller and Dr Alan Barclay in 2011, cited data on sugary soft drink consumption as a key line of evidence in support of its finding that sugar consumption in Australia had "substantially and consistently declined over the same timeframe that overweight and obesity have increased".
The pair said the data demonstrated an inverse relationship between obesity and sugar consumption in Australia.
They concluded that "efforts to reduce sugar intake may not reduce the prevalence of obesity".
"Our findings would suggest that reductions in sugar intake may have contributed to the rise in obesity," they wrote in the paper.
The paper has been widely cited by the sugary drinks industry as evidence that consumption of soft drinks has not contributed to the obesity crisis.
This includes an Australian Beverage Council submission to the National Health and Medical Research Council (NHMRC) opposing the recommendation that Australians "limit" their consumption of sugar and sugary drinks.
Professor Brand-Miller is one of Australia's leading nutritionists and is the driving force behind the low GI diet.
But following an investigation by Radio National's Background Briefing program, the journal Nutrients has posted a correction for what it called "inadvertent errors" in the Australian Paradox paper.
The investigation found the claim that Australians were drinking 10 per cent less sugary soft drinks since 1994 could not be supported by the charts published in the paper, which clearly showed that soft drink consumption had gone up by 30 per cent.
Citing industry data, the original paper stated: "Food industry data indicate that per capita sales of low calorie beverages doubled from 1994 to 2006 while (sugar) sweetened beverages decreased by 10 per cent."
But quizzed about how this claim could be made when the paper's own charts showed Australians were drinking 30 per cent more sugary soft drinks, Professor Brand-Miller conceded there may have been errors.
"It might be that a key word came out... a key word has come out, OK?"
Professor Brand-Miller said she meant to say "the amount of sugar that went into those soft drinks declined by 10 per cent".
But the correction makes clear the "inadvertent error" did not refer to a decline in the amount of sugar in soft drinks, but referred to a 10 per cent decline in market share by sugary soft drinks.
Nutrients informed its readers that "some words were missing".
It said the amended paper now reads: "Food industry data indicate that per capita sales of low calorie (non-nutritively sweetened) beverages doubled from 1994 to 2006 while market share of nutritively sweetened beverages decreased by 10 percentage points."
10 per cent drop in consumption 'nonsense'
Former Reserve Bank economist Rory Robertson said the claim that per capita consumption of sugary drinks had declined by 10 per cent was "nonsense".
"They seem to have got themselves tangled up in issues of absolute levels of sugary soft drink consumption and market shares of sugary soft drink consumption," he said.
"One of their charts highlights the fact that there has been a big increase in diet drink sales in Australia.
"What they meant to say was that sugary soft drinks sales increased by 30 per cent but the market share of sugary soft drinks dropped by 10 percentage points.
"One is relevant to the issue of whether sugar consumption went up or down and one is a furphy."
The ABC also reported other contentious data cited by The Australian Paradox, including Australian Bureau of Statistics (ABS) datasets showing sugar consumption had declined.
Those datasets were later discontinued because the ABS could no longer reliably count sugar consumption as so much of it was embedded in food and drink.
Professor Brand-Miller has stood by the claim that sugar consumption in Australia had declined.
"If children have reduced their intake of soft drinks, then it's probably likely that they've reduced their intake of added sugar in total from 1995 to 2007," she said.
But Mr Robertson says the paper is "a menace to public health".
"There is no Australian paradox; sugar consumption is up, not down," he said.
The journal Nutrients disagrees.