La nutrición lidera la desinformación: más bulos que sobre cambio climático y vacunas

A rumor circulating this August claims that during the upcoming eclipse on the 12th, people will lose weight. It is false. But it is also entirely typical of the moment we find ourselves in—a time when false claims about food have become more prevalent than misinformation about climate change, medical treatments, or vaccines.

A survey conducted by Spain's Foundation for Science and Technology (FECYT) among 2,215 people reveals the scale of the problem. Forty percent of respondents perceive nutrition-related misinformation as the dominant source of false information in their lives. Climate change ranks second at 36.2 percent. Medical treatments follow at 31.9 percent. Vaccines, despite years of coordinated campaigns against them, come in fourth at 28.3 percent. The finding is striking: we are more convinced we are being lied to about what we eat than about almost anything else.

Celia Díaz, a sociology professor at the Complutense University of Madrid and one of the study's authors, explains why falsehoods about food have become so pervasive. Digital platforms, she notes, reward content that triggers emotional responses. They amplify it, spread it, make it visible. But the real power of nutritional misinformation lies not in our inability to distinguish fact from fiction. It lies in the intensity of the emotions these claims awaken—emotions so strong they override critical thinking entirely. Díaz offers an example: a claim circulating online suggests that certain foods reduce cortisol and therefore body weight. The claim is baseless. Yet when researchers asked people why they believed it, the answer was consistent: it felt hopeful. It felt optimistic. They shared it because they wanted to believe it, and because they wanted others to believe it too. The emotional lift mattered more than the truth.

Multiple forces conspire to keep these myths alive. The food industry moves enormous sums of money. Some media outlets accept payment to publish stories about "fat-burning" foods—as if any food could work like a blowtorch on the body—or about supplements promising miracles with little or no scientific backing. Influencers peddle miraculous methods and decontextualized findings in exchange for substantial fees. Even small scientific studies, often funded by the companies that stand to profit from their results, can contradict the overwhelming consensus of established science and generate media chaos and public confusion in the process.

But there is something deeper at work. Eating is a daily act so fundamental that nearly everyone holds opinions about it based on personal experience. Someone believes a particular food is a cure-all because they felt better after eating it. Someone else avoids another food because they felt worse. These beliefs persist even when they contradict international scientific consensus or the teachings of a four-year degree program in nutrition and dietetics. As Díaz explains, because we have daily experience with food, it becomes nearly impossible to separate ourselves from something that carries so many emotional memories and vital moments. When we hear theories that contradict what we think we know, resistance is almost automatic. The British nutritionist Arnold E. Bender wrote in the 1980s: people believe what they want to believe, regardless of the facts.

There is also an identity component to eating that has grown more pronounced. Dietary choices have become ideological positions. Veganism, paleo, high-protein, low-carb, calorie restriction, intermittent fasting—these are no longer just ways of eating. They are ways of being, statements about the kind of society one wants to live in. Someone might stop drinking milk not because they dislike its taste or because it makes them feel ill, but as an expression of opposition to animal exploitation. Cooking and eating have become tools for transforming society, one meal at a time.

This identity dimension creates what might be called nutritional tribes. Belonging to one—whether it is the paleo community, the advocates of grandmother's remedies, the practitioners of Ayurveda, or those who fast—makes it difficult to question the myths that sustain that worldview. To do so risks expulsion from the group. Díaz notes that the FECYT survey did not specifically examine this identity component, though she acknowledges its importance and expresses interest in exploring it further in future research. For now, the mechanism is clear: we do not simply believe false things about food because we are gullible. We believe them because they make us feel something, because they connect us to others, because they say something about who we are.