National eating habits were rated a paltry 61 out of 100 overall by the CSIRO, which found we are eating too much junk food too often.

The Australian diet snapshot found men are more indulgent than women when it comes to consuming chocolate, soft drinks and alcohol. Retirees and people working in health care and education have better diets than those in the construction industry. The survey also found Australia's healthiest eaters are on the NSW north coast.

The ratings were given out of 100 on the CSIRO Healthy Diet Score, which assesses the quality of people's eating habits against the Australian Dietary Guidelines. More than 40,000 people were surveyed by the CSIRO about the variety, frequency and quality of the essential food groups they consumed, balanced against their intake of discretionary foods, which are high in sugar, refined starch and saturated fats, and low in essential nutrients.

The results gave Australians a fail mark when it comes to consuming junk food. We also score poorly for eating insufficient fruits, vegetables and dairy.

CSIRO research director for nutrition and health Manny Noakes said the results raised concerns over national eating habits. "The scores were fairly unflattering," she said. "If we were handing out report cards for diet quality, Australia would only get a C."

The survey found many people were having "larger portions of junk food, more often", Professor Noakes said. "This type of food is no longer just an indulgence, it's become mainstream and Australians are eating it each and every day."

The average amount of kilojoules in discretionary food consumed by each person equates to 32 kilograms of chocolate a year, she said.

The average score for the Australian diet in the discretionary food category was only 37 out of 100, based on our over-consumption of junk food. Dairy food intake also received a fail mark of 49 - but, in that case, for under-consumption of the essential food group. National intake of fruit and vegetables is also less than dietary guidelines, resulting in ratings of 67 and 68 respectively.

Australian women have healthier eating habits than men. Women's overall diet quality scored 62, against 56 for men. NSW was ranked just behind Victoria on the healthy diet score. Australia's healthiest eaters were on the NSW north coast, with the Coffs Harbour-Grafton region receiving the highest score of any area. The worst eaters were at Wide Bay, in Queensland. 

The best eaters by occupation included personal trainers and research professionals, while people working in construction, logistics and production scored lower than those who are unemployed.

Almost 15 millions Australian adults are overweight or obese. Bureau of Statistics figures show the prevalence of such conditions has increased from 56.3 per cent in 1995 to 62.8 per cent in 2011-12.

Professor Noakes, co-author of the CSIRO Total Wellbeing Diet, said many people surveyed scored highly in terms of water intake and the variety of foods in their diet. But there was "lots of room for improvement in other areas", she added.

She encouraged people to test their own diet at www.csirodietscore.com.

"To improve your diet quality, people need to cut back on the consumption of junk food and start to focus on eating smaller portions," she said. "They also need to be more mindful of every bite they take, by eating more slowly and consciously."