Nutritionists, fact-checking, and combating misinformation

Misinformation in the areas of health and nutrition is a particularly relevant topic.

In 's 2024 Global Risks Report , misinformation and disinformation were ranked as the most serious global risk in the short term.

Misinformation in the health sector undermines public trust in the information system as a whole, including trust in its professionals. It leads people to question the integrity of information sources, creating a vicious cycle of uncertainty. This vicious cycle can add uncertainty to an already anxiety-inducing context, amplifying citizens' vulnerability to misinformation and preventing them from making informed choices or finding reliable information when faced with a significant volume of news. In parallel, misinformation in the health sector tends to polarize public debates and accentuate opposition between groups.

Although health misinformation was already a significant problem before the pandemic, COVID-19 has particularly highlighted the potential impact of this issue. Simultaneously, this period has allowed for a deeper understanding of the mechanisms by which misinformation spreads and the most effective strategies to combat it.

Fact-checking has been one of the main strategies used to combat misinformation, and numerous studies have already been published on its relevance and effectiveness.

In general, the evidence points to benefits in correcting false information, but there are also risks that should not be overlooked. Although fact-checking is generally effective in reducing false beliefs, the literature points to possible unintended effects in certain contexts, including increased familiarity with false claims, maintaining the public visibility of the topic, and reduced effectiveness in highly polarized environments.

The issue is complex. Furthermore, strategies for combating and mitigating misinformation require continuous adaptation to technological evolution and the dynamics of social networks. These are more than enough reasons to reflect on misinformation (false or manipulated information shared with the intention of misleading) in food and nutrition.

Fact-checking and its relevance

In recent years, there has been a growth in scientific research on the importance of fact-checking in combating misinformation, especially following the rise of fake news on social media during specific periods such as elections, the COVID-19 pandemic and vaccination campaigns, or even scientific/food misinformation.

In general, there is consistent evidence that fact-checking initiatives can reduce false beliefs and contribute to improving critical information evaluation skills (media literacy). There is also evidence that these practices can foster perceptions of journalistic transparency and trust in scientific information, although these effects are more dependent on context and the degree of prior trust in institutions.

Relevant work by authors such as Nathan Walter and colleagues, who conducted landmark meta-analyses on the topic in 2020, and later by authors such as Ethan Porter and Thomas J. Wood, Nathan Walter and Riva Tukachinsky , and more recently Bozhena Ivanytska and colleagues, suggests that fact-checking has a positive and statistically robust effect on correcting false beliefs. However, corrections may be less effective if the misinformation has been attributed to a credible source (e.g., healthcare professionals), if it has been repeated several times before correction, or if there has been a longer time interval between the dissemination of the misinformation and the correction. Similarly, the ability to correct political misinformation through fact-checking is substantially attenuated by the pre-existing beliefs, ideologies, and knowledge of the participants, and people may continue to believe in false information even after correction.

We believe that the same could happen in the area of ​​food on highly polarized topics, such as the effect of meat consumption, vegetarian diets, or the impact of ultra-processed foods on health. It is important to highlight that these topics, which mobilize and polarize debate, are often associated with broader commercial and economic interests.

Authors such as Brendan Nyhan and Jason Reifler described in 2010 that attempts to intervene to correct fake news or episodes of misinformation can fail or even reinforce erroneous beliefs in ideologically committed groups, launching the debate about the "Backfire Effect." Subsequent studies have shown that the "Backfire Effect" is less frequent than initially thought, but it is something worth remembering. More recent experimental work by authors such as Ingrid Bachmann and Sebastián Valenzuela has confirmed that certain fact-checking formats are effective in reducing people's misperceptions; however, these positive effects in reducing beliefs come at a cost: compared to control groups, users exposed to political fact-checking trust the news less and consider the media more biased, especially after reading corrections that refute misinformation favorable to their attitudes. In this way, misinformation not only influences people's beliefs, but can also undermine public trust in the media and in reputable institutions such as the World Health Organization.

One of the most important aspects related to fact-checking is its persistence over time. Some studies suggest that the effects of fact-checking largely disappear within two weeks and do not produce lasting repercussions on beliefs. Others, specifically when fact-checking concerns political facts, argue that this process is very incomplete, reaching only a tiny fraction of prominent disinformation narratives. And that, even when shared, fact-checks are almost always disseminated within partisan communities, rather than between them.

Could this effect also be observed in the area of ​​food and nutrition, where the circulation of misinformation seems to be particularly favored by identity confirmation and bias confirmation mechanisms, in which users primarily seek content that validates previously adopted beliefs, lifestyles, or dietary practices, to the detriment of objective information geared towards decision-making?

The specificity of Nutritional Sciences

In fact, scientific literature suggests that nutrition and food constitute one of the areas most vulnerable to digital misinformation. For several reasons. For many citizens, food is not perceived solely as a technical or scientific issue capable of influencing health, but also as a moral, cultural, ideological, and identity issue. Thus, those seeking information often tend to look for content that validates already adopted lifestyles, reinforces prior beliefs, and confirms specific dietary practices, making this an area easily appropriated for influence. On the other hand, due to the strong media coverage of food and the commercial interests at stake, it is a space of great interest for promoting opinions and narratives favorable to specific products or consumption models.

This space of appropriation and confrontation with science — which is also not neutral — manifests itself particularly frequently in the relationship between food consumption and disease, in which the complexity of dietary patterns, food composition, and the multi-causality of diseases associated with diet makes it difficult to formulate definitive conclusions or verdicts.

This is a space where misinformation thrives. Although today we have gathered evidence on the high probability of a relationship between food consumption (for example, processed meat, sugary or alcoholic drinks) and the onset of disease, namely through observational studies, understanding of biological mechanisms, and systematic reviews and meta-analyses, the robustness of the association depends on the consistency of multiple associations and their meaning. This complexity is easily exploited by misinformation and the creation of doubt.

An example of these specificities in the food sector was the confrontation between the EAT-Lancet report and pro-meat campaigns such as #Yes2Meat. Although the scientific evidence was on the side of the report and its signatories, which suggested the need to globally reduce meat consumption for better health and to protect the environment, this message was heavily contested on social media and unable to overcome messages in favor of maintaining meat consumption.

Although the recommendations proposed in the report have a solid scientific basis, by ignoring cultural identity and food tradition and relying excessively on regulatory restrictions, they failed to counter an agile, highly aggressive public relations strategy heavily funded by the meat industry. The pro-meat campaigns and the influencers involved bypassed the science, appealing to emotion and successfully framing the recommendations as an attack on individual freedom and free choice by a certain scientific elite.

How can we improve the fight against misinformation?

The World Health Organization argues that combating misinformation should be based on an integrated approach, not only correcting false information, but also building public trust, media literacy, and community participation. Other authors, such as Bozhena I and colleagues, suggest the need to strategically support independent fact-checking networks, reinforce the need to integrate investment in digital literacy and critical thinking into curricula; and also the need to support national cybersecurity initiatives within the framework of public policies.

One of the central suggestions is the need to improve the quality of fact-checking. The ability to correct false or misleading information and minimize risks largely depends on how fact-checking is designed and communicated, as well as the speed of the response. The longer false information circulates without rebuttal, the greater its perceived credibility tends to be. The deconstruction of false beliefs should also avoid strategies of ridicule or aggressive confrontation on social media, as these can increase polarization, reinforce group identities, and deepen distrust of reputable institutions.

Organized and institutionalized fact-checking in Portugal really began to consolidate between 2018 and 2019, with the newspaper Polígrafo, the first Portuguese digital newspaper dedicated exclusively to fact-checking, and, later, with the television program Polígrafo/SIC, described as the first Portuguese television program dedicated exclusively to fact-checking.

Beyond fact-checking, other strategies have been explored, such as decentralized communication and the use of micro-influencers, which, in certain contexts, can prove more effective than national communication campaigns. These approaches are based on the use of interlocutors from the local community, perceived as approachable and credible, with a greater capacity to generate trust and amplify messages among specific audiences.

Another possibility is raising awareness among digital influencers and integrating critical thinking practices within these groups, as a way to reduce the spread of poor-quality health information. This was the strategy recently used by the Directorate-General of Health through the “Guide for digital influencers and advertisers – Information on the rules and best practices in the commercial communication of breast milk substitutes and foods for babies and young children in the digital environment.”

In this approach to the problem, several articles suggest the use of reference professionals, namely nutrition professionals, researchers, communicators, and educators, as regular disseminators of quality information and mitigators of misinformation (and also here). These experts can play a fundamental role in evaluating information on food and nutrition in light of scientific evidence and as a reference for interacting with citizens. However, three aspects deserve reflection. The need to improve the communication skills of nutrition professionals. Frequently, health communication is excessively technical, inaccessible, or unappealing. Effective communication should be clear, simple, emotionally relevant, visual, and easily shareable. Another important aspect is the need to avoid the pitfalls of scientific confrontation on digital platforms, where one rarely wins, giving preference to the dissemination of quality information. Finally, the need for health professionals who communicate about nutrition and food, particularly nutritionists, to clearly indicate the existence or absence of conflicts of interest whenever they communicate publicly.

Beyond healthcare professionals, leading public institutions such as universities and health institutions should play an important role in combating misinformation, including in their mission and objectives the dissemination of science and reflection on this topic. They should also create conditions so that the knowledge existing and produced within these institutions can reach citizens and, in a regular and widespread manner, other institutions in civil society. An experimental laboratory for this process in academia has been, since 2019, the portal “Pensar Nutrição – Combater a desinformação” (Thinking Nutrition – Combating Misinformation) of FCNAUP (Faculty of Nutrition, Food and Nutrition of the University of Porto).

Another dimension of combating misinformation involves strengthening the scientific, media, and digital literacy of the population. This implies improving citizens' ability to interpret scientific studies, distinguish evidence from opinion, understand the concept of scientific consensus, and verify the credibility of information sources, with public health institutions and academia actively participating in this effort. Among the strategies for strengthening scientific literacy, the concept of prebunking. This is a preventive strategy that seeks to anticipate misinformation, preparing citizens to recognize manipulation techniques and misleading narratives before they are disseminated. Instead of simply correcting false information after it has circulated, prebunking functions as a kind of "cognitive inoculation," a preventive format capable of regularly increasing people's resistance to misinformation.

Finally, the need to regulate the dissemination of false or misleading information about nutrition on digital platforms and social networks should not be disregarded, naturally ensuring a balance between protecting public health, freedom of expression, and preserving public trust. If regulation of communication by nutrition professionals in digital formats is growing, particularly through professional bodies and codes of ethics, it makes sense that, in parallel, all those who communicate on the same topics can be equally scrutinized and even sanctioned when they jeopardize the health of citizens.

In a context where information circulates faster than its verification and where authority is often confused with visibility, the role of nutritionists today goes beyond the purely clinical dimension. Combating food and nutritional misinformation requires professionals capable not only of interpreting scientific evidence, but also of communicating clearly, contextualizing recommendations, and participating actively but thoughtfully in digital spaces where citizens' decisions are influenced. The challenge now lies in creating conditions so that this participation can be effective and beneficial for citizens, reinforcing trust in the professionals involved and reducing the risks involved.