Just weeks after researchers showed a cause-and-effect relationship between ultra-processed food and weight gain, two more studies have linked these foods with disease and death.

Key points: Two European studies link ultra-processed food consumption with increased risk of cardiovascular disease and death from any cause

Two European studies link ultra-processed food consumption with increased risk of cardiovascular disease and death from any cause Evidence is mounting that it's the processing, not just the nutrient content, that makes these foods bad for our health

Evidence is mounting that it's the processing, not just the nutrient content, that makes these foods bad for our health Australia may need to look at how it labels foods to warn consumers, experts say

The pair of studies, published in the BMJ today, both looked at consumption of ultra-processed food and health outcomes and — perhaps unsurprisingly — it's not good news.

The first, which was based in France, found increasing the proportion of ultra-processed food in the diet by 10 per cent was associated with significantly higher rates of cardiovascular disease and cerebrovascular disease (such as stroke).

The second, based in Spain, found people who consumed more than four servings of ultra-processed food per day were 62 per cent more likely to die of any cause compared to those who had less than two servings per day.

In both studies, large groups of adults completed food intake questionnaires, then their rates of disease were tracked for up to 10 years.

The findings provide further weight to the already sizeable pile of evidence that highly processed food is linked to poorer health, said Mark Lawrence, who co-wrote an editorial on the topic, also published today.

We might need to reconsider what it is about these foods that makes them unhealthy, said Professor Lawrence, a food policy expert from Deakin University.

"It's not just about the the so-called 'risky' nutrients in foods," he said.

"The nature of the cause is associated with the physical and chemical changes that happen to the food as a result of this high degree of industrial processing.

"It's an independent risk factor irrespective of the presence of, say, sodium or added sugar in the food."

Australian adults get more than a third of their energy from "discretionary foods", according to a recent Australian Institute of Health and Welfare report. This definition isn't exactly the same as "ultra-processed" but there is a fair bit of overlap between the two.

What is an 'ultra-processed' food?

If the term "ultra-processed" food conjures images of fluoro-orange cheese-flavoured snacks and sour gummy lollies, you wouldn't be wrong.

But there are other foods you might not realise also fall into this category.

The NOVA food classification system 1. Group 1 - Unprocessed and minimally processed foods: Fruit, vegetables, nuts, meat, eggs, milk. May be dried, pasteurised, cooked or chilled. 2. Group 2 - Processed culinary ingredients: Oils, butter, sugar and salt. Processed to make products that can be used to cook Group 1 food but not meant to be consumed by themselves. 3. Group 3 - Processed foods: Preserved fruit and vegetables, canned fish, cheese and fresh bread. Usually made from two or three ingredients. 4. Group 4 - Ultra-processed foods: Soft drinks, packaged snacks, reconstituted meat, pre-prepared frozen meals. Contain little, if any, intact Group 1 foods. Include ingredients like sweeteners, colours, preservatives and food-derived substances like casein, lactose and gluten. Source: Open Food Facts

Packaged biscuits, sausages, instant soups and fruit yoghurts are all classed as ultra-processed under the NOVA food classification system, which is recognised by global health agencies including the UN Food and Agriculture Organisation.

Ultra-processed foods tend to be higher in nutrients we know are not good for us, namely salt, fat and added sugar, but this new wave of evidence suggests their health impact is more than the sum of their parts, said Alexandra Jones from the George Institute for Global Health.

This means a common approach for reformulating packaged foods by simply reducing their salt, fat and sugar content, or fortifying them with fibre and vitamins, might not be enough, Ms Jones said.

"This evidence suggests that perhaps there are some foods that — because they're ultra-processed — it doesn't matter what we do to their nutrient content, it's not going to make them better for us," she said.

"You basically can't make an ultra-processed food healthy by just pumping it full of nutrients.

Current food labelling in Australia focuses on salt, fat and sugar. But both Professor Lawrence and Ms Jones said evidence was mounting to suggest the degree of processing should also be communicated to consumers.

"This has implications across a lot of different areas. I think the front of pack labelling is the most tangible one at the moment," Professor Lawrence said.

"It could be something as simple as, is this an ultra-processed food or not."

Ms Jones said Australia's current labelling systems, which include nutrient breakdowns, ingredient lists and the opt-in health star ratings, were useful and evidence based — but these studies suggested we may need to go further in the future.

"As we watch this evidence evolving, we will be looking at whether we need to review all our nutritional policies to factor in processing as an additional consideration," Ms Jones said.

But that doesn't mean we should ignore information about fats, sugar and salt in a product.

"We shouldn't be scrapping what we already do know well and which is supported by a lot of evidence, which is that there's a lot of risks associated with consumption of foods which are high in salt, sugar and fat, so stay with that advice.

"A lot of these ultra-processed foods are going to be high in these nutrients anyway."