Opinion – Bruno Gualano: Nutritional Denialism

Paleo, Ketogenic, Low-Carb, Low-Fat, High Protein, Mediterranean, Anti-Inflammatory, Dot, Blood Type, Vegetarian. There is no shortage of candidates for the ideal diet post — a subject that is subject to heated debate in offices, social networks and the gym. On the other hand, it is rapidly moving towards a consensus on what should be avoided: ultra-processed food.

Ultra-processed products are industrial formulations with a high content of salt, sugar, fat, and countless additives that catch the tongue of citizens who do not hold a PhD in Food Engineering. High intakes of these foods are associated with increased risks of several chronic diseases, obesity and premature death. This is what motivates the Food Guide for the Brazilian Population to discourage the regular consumption of packaged biscuits, sugary breakfast cereals, instant noodles, powdered juices, soft drinks, snacks, sausages, among other pseudo foods.

It makes sense? Of course, not for the ultra-processed industry…

The guide – extolled worldwide by health professionals, policy makers and scientists – suffers from constant attacks orchestrated by the industry and its lobbyists (including scientists). The criticisms, however, are so unfounded that they border on denial.

Although several observational population studies clearly point out the association between the consumption of ultra-processed products and worse health rates, detractors of the guide often cast doubts on the causality of this relationship. In fact, as discussed here, observational studies in the field of food are prone to bias, many of which can only be effectively remedied by controlled clinical trials.

With this in mind, scientists at the NIH (National Institutes of Health) —the leading agency for medical research in the United States— have carried out innovative work on the topic. The research was conducted in a metabolic unit, where the participants resided throughout the study, allowing researchers to have strict experimental control.

In the study, people with stable weight were subjected to two different diets: one rich in ultra-processed foods and the other in unprocessed foods. Both were composed of carefully planned meals, which contained the same amount of calories, sugar, salt, fiber, fat and protein. Participants tried each of the diets for 2 weeks, in random order, and were instructed to eat as much as they wanted.

When exposed to the ultra-processed diet, people consumed about 500 kcal per day more than under the unprocessed diet. Immersion in ultra-processed cuisine also yielded about 1 kg on the scale, while the “detox” provided by the diet rich in fresh foods eliminated about 1 kg of the participants.

By mechanisms that we are still completely unaware of, ultra-processed foods seem to bypass our central appetite control systems, resulting in excessive energy intake, body weight accumulation and its known deleterious health effects. Therefore, as the authors of the aforementioned study conclude and our guide recommends, limiting the consumption of ultra-processed products represents an important strategy to combat obesity.

Science produces evidence, but it does not dictate the direction of the market. Ultra-processed products are cheap, last on the shelves and, without the restraint of satiety or the impulse to hunger, are consumed in large volumes. The appeal of collective health would not be enough to convince the industry to reformulate its products, giving up generous profit margins.

Until then, a game played, as the master Elio Gaspari would say. If money commands, the industry obeys. In several countries, taxing policies for ultra-processed products —in particular for sugary drinks— were effective in reducing their consumption. In Brazil, if soft drinks and juices with added sugar were taxed at 20%, as requested by the WHO, it is estimated that the prevalence of obesity would drop by 11.8%. It is time to seriously consider these measures.