Sugar not calories are to blame for the obesity and diabetes epidemic in Australia, which is why there is a responsibility to introduce a sugar tax, says endocrinologist and childhood obesity expert Professor Robert Lustig.
The US anti-sugar advocate has set his sights on Australia's burgeoning waist lines and will argue the case for a tax on sugar at the 5th BioCeutical Research Symposium in Sydney this weekend.
Prof Lustig says sugar is "toxic" and addictive, like alcohol and cocaine, and is harming the future health of our children.
"Fixing the obesity epidemic isn't as simple as 'calories in, calories out'. It depends on where those calories come from and it depends on how those calories are metabolised," Prof Lustig said.
"When you remove added sugar from the diet, even when calories remain the same, virtually all aspects of metabolic health are improved, regardless of weight change."
Because of the way sugar is metabolised the liver has no choice but to turn excess sugar into liver fat, says Prof Lustig.
It is now known that this liver fat is the driver of all the chronic metabolic diseases including type 2 diabetes and heart disease.
"There is also indirect evidence that it can cause cancer and dementia," said Prof Lustig.
Two thirds of Australian adults and one in four children aged 5-17 are classified overweight or obese.
Around 1.7 million Australians have diabetes, and according to Diabetes Australia an estimated 500,000 people are living with type 2 diabetes without knowing it.
Prof Lustig says blaming obesity and diabetes on the individual is short-sighted, and society must intervene to tackle this public health "crisis", much like the battle against tobacco.
"We require both personal intervention and societal intervention, rehab and laws," he said. "For alcohol we have needed both, for tobacco we needed both and for obesity and diabetes we will also need both."
"One of the problems that we have is that people consider obesity to be a moral failing, a personal responsibility issue and therefore why would you get society involved. That is not true."
Prof Lustig says this wrong belief system has been "manufactured by the food industry to deflect culpability".
The science shows there is a need for a sugar tax because the human body was only designed to process small levels of glucose, says Prof Lustig.
Fructose, the "addictive" sugar added to food to make it taste sweet, is completely unnecessary to human health.
Yet the food industry has used sugar as the "hook" to get people to consume more food.
"They have realised that when they added sugar to the food we bought more, it's the hook because sugar is addictive," Prof Lustig said.
"The problem is, what are we going to do about this legal addiction?
"We have to have intervention of some form, and taxation is one way of doing it.
"Reducing availability reduces consumption which reduces health harms, that's the iron law of pubic health."
