Better understanding the potential health effects of ultra-processed foods
‘Ultra-processed’ foods are part of the food supply, but they also raise some health concerns. That being said, the concept of ultra-processing has yet to be scientifically substantiated. In light of this, ANSES has reviewed the available studies on the subject. Its expert appraisal identified several signals suggesting a relationship between the consumption of such foods and a higher risk of developing chronic diseases. Now, the challenge is to identify the mechanisms that underlie these risks. Among the avenues to be explored, the Agency recommends focusing on the effects of new substances that can form during food processing. It also stresses that other courses of action should be considered to improve nutrition in the population.
What exactly are ultra-processed foods?
A wide variety of processing methods (cooking, fermentation, fractionation, etc.) are used that influence the quality and safety of products in different ways. In its expert appraisal on ultra-processed foods, the Agency pointed out that there is currently no consensus on the definition of these types of foods. It therefore studied the existing classifications based on the degree of food processing, in particular the Nova system. Developed by Brazilian researchers, Nova is currently the most widely used framework in epidemiological studies.
In the Nova classification system, ultra-processed foods are characterised by the use of certain processing methods and the addition of ‘cosmetic’ additives and substances, such as protein isolates or hydrogenated oils, that are seldom used in meals prepared at home. These additives and other added substances are intended to modify the texture or taste of the food or make it easier to prepare. In general, this system is based on the presence of additives and substances without distinction, making its application subjective.
Signals to be further investigated
Despite these limitations, the Agency conducted a systematic review of the scientific studies published on this topic. It concluded, albeit with a low weight of evidence, that a higher level of consumption of foods classified as ultra-processed under the Nova framework – the most commonly used system – is associated with a higher risk of mortality and chronic diseases such as type 2 diabetes, overweight, obesity, cardioneurovascular diseases, and breast and colorectal cancer.
Several possible underlying mechanisms
To explain the potential relationship between health and the consumption of ultra-processed foods, ANSES is making the following assumptions:
- the formulation of these foods, often designed to be convenient and appetising, and the circumstances in which they are consumed (fast-food restaurants, in front of a screen, on the move, etc.) promote excessive food intake;
- the methods used to process foods can lead to the formation of new substances, some of which are potentially harmful and can be responsible for interactions.
Carrying out studies to explore these assumptions would help better characterise the relationship between processing methods and health effects, to be able to guide public policies on food and nutrition.
Identifying courses of action to improve public health
According to the most recent Esteban health study published in 2024 by Santé publique France, the prevalence of overweight and obesity is increasing in France. The same is true for levels of physical inactivity and sedentary behaviour. Moreover, according to the latest INCA study, food consumption levels remain far from the recommended dietary guidelines.
In this context, the possibility of ultra-processed foods having negative health effects has been raised. Nevertheless, following ANSES's expert appraisal, it appears that the current classifications of foods based on their degree of processing cannot be translated into health risks. This means that these classifications cannot be used for the purposes of nutritional education.
Beyond the issue of ultra-processing, the Agency emphasises the importance of evaluating the effectiveness of all the collective courses of action already implemented to reach the recommended food consumption guidelines, as well as the levels of daily physical activity and break in sedentary behaviour advised for the entire population.