Most ultra-processed foods are characterized by their low satiating capacity, high calorie density, and appealing sensory factors, making it easy to consume large portions, which is especially true for individuals exposed to various factors favoring passive overconsumption. In particular, their high sensory impact, which probably underlies the rewarding properties associated with the consumption of such foods in mammals, is at the heart of central, hormonal, and metabolic dysregulations. As far as the influence of the microbiota is concerned, the intake of energy-dense ultra-processed foods would modulate its composition and function because of the high content of rapidly absorbable macro- and micronutrients and the presence of substances promoting the growth of harmful bacteria. The intriguing findings of epidemiological research must certainly be confirmed, along with those reported in this review, in well-conducted experimental studies, benefiting from various collaborations among different research disciplines, and cause-effect relationships need to be established in the future.
Epidemiological evidence has shown that individuals consuming ultra-processed foods, which are industrial formulations that are typically high in sugar, fat, and salt, are at a greater risk for developing obesity, heart disease, hypertension, type 2 diabetes, and several cancers. According to a Nutrient Profiling Model, an algorithm for assessing the healthiness of foods, in general, ultra-processed foods are nutritionally poorer compared with non-ultra-processed ones, despite being energy-dense. Although this observation explains why their consumption can lead to nutrient inadequacy, it is only the most discernible consequence in the long term, which is unfolding as a significant public health problem. What is causing those adverse health effects has not been unraveled to date. Three non-exclusive, biologically interconnected mechanisms make them plausible culprits: interference at different stages in the regulation of calorie intake, metabolic dysregulations, and imbalance of the microbiota composition and function.
Definition of Ultra-Processed Foods
Ultra-processed foods take longer to eat. Several hypotheses were raised to explain the observed association. Investigation was performed for 15,362 participants. Participants in the first tertile of ED were more likely to be men, smokers, living alone, and less physically active as compared with those in the third tertile, after adjusting for sociodemographic, lifestyle, and psychological variables. They also presented lower intakes of macro and micronutrients. In logistic regression, individuals of the first ED tertile were associated with higher odds of choosing physical rather than sensory parameters of meals, and in the second tertile choosing wars to support that association do exist. This review aims to detect the causes responsible for the different speeds of food ingestion, the resulting decrease in hunger suppression and diminished satiety, which both overweight and normal weight individuals experience with their consumption of diets high in ultra-processed foods.
Ultra-processed foods or foods derived from substances not typically used in cooking, like flavors, colors, and other additives, are of concern because of the growing body of evidence suggesting an independent link with a range of diseases, including cardiovascular disease, cancer, and diabetes. According to the NOVA food classification, ultra-processed foods are defined as industrial formulations typically with five or more, and usually many, ingredients, such as sugar, oils, fats, salt, antioxidants, stabilizers, preservatives, flavor enhancers, colorants, emulsifiers, humectants, non-sugar sweeteners, modified starches, and other cosmetic additives designed to create products that are ready to eat or drink. This may include several food substances prioritized for their functional properties rather than their nutritional value. Moreover, it has been part of major changes in dietary patterns with higher proportions of foods eaten that are indeed ultra-processed.
Health Effects
There may be additional health impacts associated with consuming ultra-processed versus less-processed foods: a new study found that a diet of ultra-processed foods increased ad libitum calorie intake and weight gain in comparison with a diet of minimally processed foods. Importantly, this study was conducted under controlled conditions, and the between-group number of calories consumed each day was not significantly different. Moreover, the individuals eating ultra-processed foods were presented with a buffet, while the others were offered meals as part of the study protocol.
Ultra-processed foods are calorie-dense and high in added sugars, sodium, and unhealthy fats, and they are low in protein, fiber, and micronutrients. Diets high in ultra-processed foods are associated with obesity and non-communicable diseases, such as coronary heart disease, stroke, type 2 diabetes, and cancer. Though it is common for dietary intervention studies to focus on energy balance (consuming more calories than are expended), the effects of food quality on the development of disease are also relevant for individuals who are not overweight.
Nutritional Deficiencies
About vitamin replacement, it could well be asked what is the problem if people obtain their intake from over-supplemented products. Indeed, specifically in label-reading contexts, nutritional product population through an artificial, excess-supplementation plan resembles more a similar policy applied to flour, an intentionally overfortified example to illustrate the weight that can be given to imbalances in a program with the ideal goal of protecting the nutrient intake of the entire population: but that is also a goal possibly better achieved without public funds through the education of the consumer (not to be taken for granted) who decides to consume those products as replacements. The damage is social, not individual, and it is necessarily associated with increased market obesity because looking collectively at the results of many for-profit interventions that aim to serially reformulating new products and brand squaring among the different brands in the space of nutritionally poor, energy-rich products of the market (to which population-food available products contribute), the decrease in undernutrition can easily be countered by the relative and absolute growth of consumption of foods and drinks that are silently rich in a small number and generally highly correlated series of ultra-processed, non-communicable disease determinants. In reality, a thorough reappraisal of the sophisticated fluctuation between many different artificial nutrient exchanges and food alterations occurs, leading to the paradox that ultra-processed products may become some of the most likely causal factors in the genesis of NCDs.
In certain cases, ultra-processed foods can actually cause specific nutrients to be not only lost during processing but artificially replaced or boosted with other elements at much higher levels, to the point where such alterations can cause negative health effects. This is the problem of nutritional misinformation by excessive processing (not to be confused with the quite different problem of nutritional misinformation regarding the nature and effects of these products). The result, for example, of adding an excessive amount of vitamins and minerals to an already ultra-processed item aiming to give it the “healthy food” image of a food (headline 1), is that those vitamins and minerals are overdosed if people end up eating it ultra-frequently. Hyperkaline syndromes as a consequence of the excess alkalization of ultra-processed foods (or of many soft drinks, including artificially flavored and colored bubble water) offer a potent illustration.
Impact on Chronic Diseases
There is no disagreement among the authors about the evidence and the associations in the full set of detailed statistical analyses, independently of the statistical imitation in the design, execution and publication of omissions, disqualifications, insinuations and contradictions that occur in public and scientific debates. The overwhelming evidence in epidemiological work of the lack of credibility of statistical significance suggests instead that it is perhaps not very informative to undertake further prospective cohort studies: the main role of prospective cohort research may thus be to place the magnitudes and relations estimated by randomized clinical trials in a wider context.
A large body of clinical and epidemiological evidence shows that, compared to minimally processed or unprocessed foods, a high consumption of ultra-processed foods (UPF) is associated with excess weight, obesity and related complications, and the decrease or loss of the capacity to know and decide about what and how much to eat. Establishing causality is beyond the scope of this article, but the weight of evidence is large and compelling, as corresponds to an important global health problem: results from randomized clinical trials, prospective cohort and cross-sectional studies, employing traditional cohort and dietary analytic methodologies, controlling and not controlling for obesity and dieting for weight loss, analyzing different chronic non-communicable diseases such as the risk of incident cardiovascular diseases, digestive diseases and irritable bowel syndrome, metabolic syndrome, excess weight, obesity, diabetes and glucose-insulin homeostasis, cancer, osteoporosis, frailty, depression, insomnia, food addiction and sex hormones, studying different kinds of UPF and controlling for all sources of potential bias are remarkably consistent.
Cardiovascular Diseases
The Western diet, characterized by a high intake of ultra-processed foods, is recognized as a risk factor for the development of atherosclerotic cardiovascular disease. In 2017, the estimated number of deaths from CVD was 17.7 million, with a mortality rate higher in countries where ultra-processed foods are widely consumed. The regular consumption of ultra-processed foods favors endothelial dysfunction, inflammation, insulin resistance, lipoprotein (a) elevation, hypertension, and obesity, all of which are directly related to the onset of cardiovascular diseases. The fact that ultra-processed food has a heterogeneous nutritional content, with poor food quality being generated by a high glycemic load, insulin resistance, the indigestible fraction of ultra-processed foods, as well as poor antioxidant content that modulates the inflammatory response, is debatable.
Environmental and Social Implications
Studies of the neotropical countryside have noted how the advances of the ag-food system disproportionately affected the poorest inhabitants. A report published by the United Nations Economic Commission for Latin America and the Caribbean (UNECLAC) indicated how the current forms of production that dominate the rural world do not just lead to depopulation, resulting in the disappearance of populations and the reduction of possibilities of employment of the rural population, but create unequal conditions in different areas that can result in social and environmental conflicts. The UNECLAC report suggested diversifying food systems and diversifying diets. In these ways, food systems would anticipate, rather than respond to, increasing chronic diseases, malnutrition, and obesity. The measure will ameliorate regional gaps in the availability of healthier foods.
Institutional well-being provides the societal and employment framework for the functioning of all professionals in the food system. Environmental well-being is derived mainly from sustainability criteria. Environmental well-being has been framed within the sustainability of the food chain. The inorganic nutritional compounds of UPFs (Ultra-Processed Foods) take their toll on the environment. Agricultural production, livestock, and fisheries contribute substantially to the degradation caused by food production and consumption. The massive use of pesticides and fertilizers, given that 76% of UPFs contain sugar, 38% fats, and 18% dairy, with a large use of water and the massive food wasting, contribute to the environmental burden of eating UPFs that boost double weight.
Sustainability
The different categories are linked by the concept of ’embodied energy’, which is rising in importance as a driver of the need for responsible consumption. The issue of diet and sustainability is a natural one, as the resulting nutritional patterns have been linked to several chronic diseases and their consequent health complications. Although most of these diet-disease relationships are disputable, many findings also point to the overall unsustainability of the current food distribution and consumption models. These unsustainable consumption patterns are supported further by the success of the so-called hell profits, which comes from the production and marketing of ultra-processed foodstuffs. These foodstuffs have indeed been marketed successfully mainly because of their affordability and heat-and-serve convenience. Their questionable nutritional quality has been experimentally and epidemiologically associated with the emergence of NCS, such as obesity and diabetes. These foodstuffs are also one of the reasons for the rise of the low-quality calorie diet, which has been associated with obesity and other non-communicable chronic diseases. These adverse health effects drive us to find ways and to call for reductions in the consumption patterns of these foodstuffs that are linked to the food systems.
This category includes one article that calls for a reconsideration of the commonly accepted calls for the reduction in ultra-processed food consumption. The focal argument is that high consumption of these foodstuffs is perhaps the price we are required to pay for having reduced poverty in many corners of the globe, and for providing food security to populations which 60 or 70 years ago were demonstrations of malnutrition and hunger. The article also reduces reservations about forthcoming evidence that these foodstuffs are the cause of various types of the explosion of NCS and diet/disease relationships as the authors believe that the evidence available up to now is not so clear-cut or strong. It also poses the question of whether it is acceptable to be a factor in the demand for certain foodstuffs, to publicize certain types of foodstuffs, and then to impose on others restrictions that would reduce our possibly (desirable) purchases (with minimum margins), ‘forcing’ these ‘others’ to conclude that it is only dystopia that generates food consumer ecosystems. It should be noted that in the current edition the same authors express opposite views in other chapters, just showing the existence of these debates.
It is becoming clear that food production and consumption are responsible for at least 20% of the emissions of greenhouse gases that are causing climate change. Nonetheless, the food industry’s priority is to increase their sales and profits. In fact, their financial resources and political capacities are great enough to shift the costs of the nutritional and environmental damage their products do to individuals and the public purse. Moreover, those companies are also able to shift the responsibility for these health problems to consumers, whom they regard as “free to choose” amongst the thousands of products available. The reality is much more complex, and something must be done. First and foremost, educational programs, media and social networks, and healthcare professionals need to convey a realistic vision of these disguised dangers in order to bring about changes in the lifestyles and dietary choices of individuals, unless the financial interests and power of the organizations involved in this issue to modify their behavior comply with their social responsibility. Furthermore, policymakers need to devise measures to discourage the manufacturers of ultra-processed foods from producing so many and promoting them so intensively.
Substantial evidence indicates that ultra-processed foods are bad for people’s health. They underlie excess intake of nutritionally poor and energy-dense types of fat, added sugars, and sodium, and inadequate intake of essential nutrients and dietary fiber in the diet. Their consumption is linked with overweight and obesity, metabolic syndrome, type 2 diabetes, inflammatory and digestive disorders, and an increased risk of cancer and other chronic non-transmissible diseases. Policies aimed at lowering the consumption of ultra-processed foods are urgently required, but there is increasing evidence related to overconsumption of environmental resources, biases of large transnational corporations against healthy diets, and the impacts of global merchandise and service trade treaties on the consumption and production of these products, which indicates that policies targeting the supply of ultra-processed foods are also necessary.