A new study by Monash University researchers shows eating chocolate and potato chips could lead to an increased risk of kidney disease.
The danger comes from harmful chemical compounds called advanced glycation end (AGE) products, which are added to processed food by chemists looking to enhance flavour.
The AGEs can "switch on" warning signals inside the body that lead to an inflammatory response.
The study was done by feeding laboratory rats food that had been heat-processed to increase its AGE content.
After 24 weeks of "chronic consumption" of the food, the rats were much more likely to develop symptoms of kidney disease compared with a control group of rodents that ate other types of food.
But there are foods that can counteract those harmful effects, including oats, beans and potatoes, the researchers said.
Other counter agents include cooked and cooled rice, barley, legumes such as black beans and peas, and raw potato starch.
"These foods are important as they get down into your lower gut and basically serve as food for your gut bacteria," associate professor and study author Melinda Coughlan said.
" The gut bacteria ferment these food-producing metabolites that are anti-inflammatory.
"Now that we have shown that it is certain chemical compounds found in highly processed foods that play a role in chronic kidney disease, we can look to make alternative food formulations or functional foods aimed at dampening the body's response."
The researchers said processed food has become a diet staple in many parts of the world, but the exact mechanisms by which the food impacts health is in need of urgent further research.
Coughlan said her new study was an important step towards understanding that issue.
"Given the increasing interest in the effects of processed food on health, we believe that these findings represent an important step towards understanding and countering the detrimental features of the modern diet," she said.
"Dietary change, as with most behaviour change, can be difficult to maintain long term, but by adding more foods high in resistant starch fibre and steaming and stewing cooking practices we can help dampen the harmful effects."
Other processed foods that tend to contain AGEs include bread, bakery products, and confectionery.
Chronic kidney disease affects 10 per cent of the global population.