Australian of the Year Dr James Muecke wants a major overhaul of the country's dietary guidelines to discourage sugar and refined carb consumption.

Australian of the Year Dr James Muecke has demanded an overhaul of the nation's dietary guidelines, saying humans were for the first time in history "overfed and undernourished" due to sugar and refined carbohydrates.

Dr James Muecke, an Adelaide-based eye surgeon, has throughout 2020 called for a crackdown on sugar in drinks and processed foods.

A sugar tax - which Canberra does not support - is central to his campaign.

He told the National Press Club on Tuesday that type-two diabetes was the leading cause of blindness in working-age Australian adults - a disease primarily caused by the over-consumption of sugar, refined carbohydrates and ultra-processed foods which are cheap and accessible.

Cereals and processed grains fall into this category.

Yet Australia's dietary guidelines, last updated in 2013, discourage excessive consumption of foods with natural saturated fats such as red meat or dairy.

As a result, Dr Muecke said this recommendation shifted consumption patterns towards low-fat, highly-processed products with added sugar.

This was despite a lack of evidence connecting natural saturated fats with cardiovascular disease, stroke or type-two diabetes.

"Why would anyone knowingly put themselves at risk of an illness that would give them decades of unnecessary medical appointments, crippling expenses, lost work and life opportunities?" Dr Muecke said in his address.

"Perhaps because they're not aware the low-fat, high-carb diet they've been consuming for the past 40 years may be causing them harm."

Dr Muecke said he'd written to the National Health and Medical Research Council this year to request a review of the guidelines, but the federal public health research body denied the guidelines contained biases.

He suggested the guidelines were geared towards "healthy adults" - despite two thirds of Australians being overweight or obese.

"It's the nutrient-deficient, energy-dense calories that are the problem, the sugar and refined carbs and unhealthy fats in ultra-processed foods that are the problem. (They are) at least half our current diet," Mr Muecke said.

"Supermarket shelves and check-outs are loaded with these diabolical foods."

Dr Muecke also said current recommendations for type-two diabetes, including eating high-carbohydrate diets, were making the illness worse.

He said there were three successful ways to place type-two diabetes in remission - low calorie diets, low carbohydrate diets or bariatric surgery. Of these, he said the low-carbohydrate diet was the easiest solution.

"Dietary recommendations within the guidelines .. are borne out of weak and unreliable epidemiological data," Dr Muecke said.