A recent article at Natural News, argued the the typical American diet is a disease threat, and even a short exposure to a high sugar, high saturated fat, low vitamin diet can cause numerous health problems. The same could be said for the fast food diets that Australians are eating:
https://www.naturalnews.com/2019-01-27-western-diet-is-a-disease-vector-on-par-with-influenza.html
“In fact, the Western diet is so bad that studies have shown that even a short amount of exposure to it can raise your chances of cardiometabolic disorders like heart disease and diabetes. In a study that was funded by the American Heart Association, female rats were fed the equivalent of a typical American diet, and those mice showed common symptoms of diabetes like high blood pressure and blood vessel damage, even after a short time, when compared to a control group. In addition, these rats had four times more fat in their abdominal area than those in the control group, despite some of them not appearing to be obese. This indicates that the negative effects of this way of eating might set in long before traditional disease markers become obvious. In a human clinical study, participants who ate hamburgers quickly experienced pathological changes in blood vessels, including oxidative stress, inflammation, and vasoconstriction. Interestingly, the mere act of adding avocado to the burger canceled these effects out in a different group. It’s easy to see how giving one’s diet a complete overhaul could have a significant positive impact on their overall health.”