We are constantly being told to eat less ultra-processed foods.
Over the years, a number of studies have warned of the dangers of eating too many cookies, cakes, and chips.
Yesterday, researchers added to the growing body of evidence, publishing two studies suggesting that too much increases the risk of a life-threatening heart attack or stroke by nearly a quarter.
But what are ultra-processed foods? MailOnline has laid out exactly what falls into this category.
Nutritionists divide foods into three groups based on the amount of processing they have gone through. Minimally processed foods, like apples, are often exactly as they appear in nature. Processed foods, like applesauce, have gone through at least one level of processing that has changed their original form. By contrast, ultra-processed foods, like apple jellies, have gone through multiple levels of processing and are often loaded with extra fats, colors, and preservatives.
Processing refers to adding or altering raw ingredients. This can be done to make the food safe to eat, such as pasteurizing, increase shelf life, such as by freezing, or improve flavor, such as by adding sugar, salt, or fat.
The Nova classification system divides foods into four groups.
It was created by Brazilian scientist Carlos Monteiro in 2009 as a way to study food groups in relation to the processes they undergo. Since then, it has been used by hundreds of scientists to examine the link between eating habits and disease.
Unprocessed or minimally processed foods are often exactly as they appear in nature. They may undergo minimal processing, such as removal of inedible parts.
Fruits, vegetables, seeds, meat, eggs, and milk fall into this category.
Processed ingredients are foods that are used in the cooking process, such as oil, butter, sugar, and salt. They are usually not eaten on their own.
A third category, processed foods, includes items that have been modified to make them taste better or last longer.
Canned vegetables, canned fish, fresh bread and cheese are all examples.
The last category, ultra-processed foods, has received more attention in recent years. These foods have gone through multiple levels of processing and are typically full of extra fats, colors, and preservatives.
While chocolate, cakes, cookies, chips, soft drinks, chicken nuggets, and French fries are obvious examples, some low-fat flavored yogurts also fall into this category, as well as bread, mass-produced breakfast cereals, pasta sauces and protein bars. and plant-based milk.
Numerous studies have linked this entire category of food to health problems like obesity, diabetes, cancer, and even dementia.
Now a combination of Australian and Chinese studies suggests that they might also harm the heart.
A Chinese analysis of 10 studies involving more than 325,000 people, conducted by the Fourth Military Medical University, found that those who ate the most ultra-processed foods were 24 percent more likely to have a heart attack, a stroke or angina.
And a 15-year-long study from the University of Sydney that included 10,000 women found that women who ate the most ultra-processed foods were 39 percent more likely to develop high blood pressure than those who ate the least.
However, the studies, like many before them, are observational, meaning they can’t prove ultra-processed foods are to blame.
The scientists suggest that other factors, such as poorer people, who are more likely to have health problems and not exercise or smoke, are more likely to eat many of these foods, could be influencing the data.
Professor Gunter Kuhnle, a nutritionist at the University of Reading, said: “Ultra-processed foods have become a buzzword to explain associations between diet and poor health, and many studies have attempted to show such associations.”
“Most of the studies have been observational and have a key limitation: It is very difficult to determine the intake of ultra-processed foods using methods that are not designed to do so, so the authors have to make a lot of assumptions.

A combination of Chinese and Australian studies suggests that eating ultra-processed foods could increase the risk of having a heart attack or stroke by nearly 25 percent and the chance of developing high blood pressure by up to 39 percent.
“Bread and meat products are often classified as ‘ultra-processed’, although this is often not true.”
He added: “Diet is one of several factors that can affect cognitive function and it is important to understand the relationship in order to make recommendations.”
“However, these recommendations must be based on sound data, taking into account the risks and benefits and other implications, for example the cost of different foods and the respective impact on health.”