A few years ago, processed food became one of the main suspects to have caused the obesity pandemic. However, processed foods include all products that have undergone some kind of processing for reasons of digestibility, preservation, palatability etc. This includes products that are generally accepted as healthy, such as chopped cabbage, cheese, slices of fruit, whole grain bread and frozen fish. So now, the finger is pointed to 'ultra-processed food'.
Surely, if there wouldn’t be any ultra-processed food available, there probably wouldn’t be as much obesity and non-communicable diseases (NCDs) in the world. Baking a cake, smoking fish, or chopping fruit takes time and effort, much more than buying these products ready-to-eat in a supermarket or bakery. We wouldn’t have any time left if we’d have to make or bake everything we eat. And it should be noted that the processing of food by industry has enabled people, especially women, to spend time building their career and focus on self-development.
But are we really trading health for convenience? What exactly is ultra-processed food? And is there some sense in the claim that we should avoid these foods? Is it really the processing that makes the food bad for your health or is the devil in the ingredients?
The terms processed and ultra-processed foods come from the NOVA classification method[1], a method that is increasingly used by health authorities to classify food according to the extent and purpose of food processing. Minimally processed products with additions like sugar, salt, oil or processed ‘culinary’ ingredients are defined as ‘Processed foods’. These usually contain 2 or 3 ingredients and the unprocessed versions remain recognizable as such. The processing is done to extend shelf life and/or enhance the taste. According to this NOVA classification, ‘ultra-processed food’ contains over 5 ingredients (what about the products containing 4 ingredients?) that include sugar, oils, fats, salt, anti-oxidants, stabilizers, and preservatives. They are ready to eat/drink/heat and aggressively marketed.
This rather arbitrary and subjective subdivision[2] makes it impossible to draw a clear line between de two (what about products that are not recognizable as the original product containing 2 ingredients?), which makes studying and comparing the groups a challenge. Also, it seems like an odd assumption that the number of ingredients would have a causal relation with health-related outcomes. Nevertheless, the relationship between ultra-processed foods and health have been the subject of many studies in recent years.
Research suggests that high consumption of ultra-processed food is bad for your health. It has been linked to excess weight and obesity[3], dyslipidemia[4], metabolic syndrome[5] and enhanced mortality[6]. Also, several studies have reported a higher risk of weight gain or obesity with the consumption of specific foods that would fall under ultra-processed, like sugary beverages and fast food[7]. The other way around, consumption of many unprocessed foods have been negatively correlated with weight gain (for example whole grains, fruits and vegetables)[8].
Stating that ultra-processed food is unhealthy would mean that the fact that food is processed is the cause of its adverse health effects. It is however way more likely that the nutrient content of ultra-processed products, is the cause of this relationship (this is called ‘confounding’ in statistics).
Ultra-processed food is indeed often high in nutrients that are shown to enhance the risk of diet-related problems like obesity and metabolic syndrome. These nutrients include energy, sugar, salt, and saturated fats. But it’s too simplistic to claim that all ultra-processed foods are unhealthy by definition. This claim should, therefore, be avoided, as the degree of processing does not necessarily reflect the content of nutrients that contribute to diet-related diseases.
People prefer clear and easy messages when it comes to nutrition advice (‘drink 2 liters of water a day’, ‘eat colorful’, ‘avoid carbs’, ‘choose superfoods’). ‘Avoid ultra-processed food’ sounds clear and easy and most people have a sense of what it means[9]. Taking into account that research shows that a large part of ultra-processed food can be classified as rather unhealthy based on their nutrient content, this would suggest it could be a good idea to advocate against ultra-processed food.
However, in the last decade, leading food and beverages producers have made great efforts to make their products healthier. This trend is likely to continue and innovation and product reformulation will probably ultimately lead to healthy, but still ultra-processed food. We should, therefore, avoid creating even more consumer confusion and distrust in nutrition messages than there is already and start communicating what is really the cause of weight gain and NCDs: the nutritional content of these products.
There is already a great number of processed food products that are healthier than their non- or less processed alternatives. Butter is less processed than (soft) margarine, but contains less unsaturated fatty acids and more saturated fat. The reduced-salt variant of industrially produced soy sauces requires an extra processing step to remove 40% of the salt content. Like to spread your bread with honey? Honey is composed of 80% sugar. Low sugar fruit spreads, on the other hand, contain about 40%.
Besides the importance to provide consumers with truthful information, it is a bad idea to create a public fear for certain products. Processed foods have been ensuring safe, diverse and accessible food supplies[10] and have been shown to contribute for a large part to meet micronutrient recommendations for individuals[11]. Fear of processed products could lead to an unvaried, unbalanced diet for some. It would be a so much better strategy to communicate to consciously consume both processed and unprocessed foods and learn consumers where to look for within the ingredients list.
[1] Monteiro CA, Cannon G, Levy RB et al. NOVA. The star shines bright. [Food classification. Public health] World Nutrition January-March 2016, 7, 1-3, 28-38
[2] Michael J Gibney, Ciarán G Forde, Deirdre Mullally, Eileen R Gibney; Ultra-processed foods in human health: a critical appraisal, The American Journal of Clinical Nutrition, Volume 106, Issue 3, 1 September 2017, Pages 717–724, https://doi.org/10.3945/ajcn.117.160440
[3] Canella DS, Levy RB, Martins APB, Claro RM, Moubarac JC, et al. (2014) Ultra-Processed Food Products and Obesity in Brazilian Households (2008–2009). PLOS ONE 9(3): e92752.
[4] Rauber, F., Campagnolo, P. D. B., Hoffman, D. J., & Vitolo, M. R. (2015). Consumption of ultra-processed food products and its effects on children’s lipid profiles: A longitudinal study. Nutrition Metabolism and Cardiovascular Diseases, 25(1), 116–122.
[5] Tavares, L. F., Fonseca, S. C., Garcia Rosa, M. L., & Yokoo, E. M. (2012). Relationship between ultra-processed foods and metabolic syndrome in adolescents from a Brazilian Family Doctor Program. Public Health Nutrition, 15(01), 82–87.
[6] Schnabel L, Kesse-Guyot E, Allès B, et al. Association Between Ultraprocessed Food Consumption and Risk of Mortality Among Middle-aged Adults in France. JAMA Intern Med. Published online February 11, 2019. doi:10.1001/jamainternmed.2018.7289
[7] Poti J.M., Braga B. Ultra-processed Food Intake and Obesity: What Really Matters for Health-Processing or Nutrient Content? Curr. Obes. Rep. 2017;6:420–431. doi: 10.1007/s13679-017-0285-4.
[8] Hruby A, Manson JE, Qi L, et al. Determinants and consequences of obesity. Am J Public Health. 2016;106(9):1656-1662.
[9] Gastón Ares, Leticia Vidal, Gimena Allegue, Ana Giménez, Elisa Bandeira, Ximena Moratorio, Verónika Molina, María Rosa Curutchet, Consumers’ conceptualization of ultra-processed foods, Appetite, Volume 105, 2016, Pages 611-617,ISSN 0195-6663, https://doi.org/10.1016/j.appet.2016.06.028.
[10] Floros JD, Newsome R, Fisher W, Barbosa-Cánovas GV, Chen H, Dunne CP, German JB, Hall RL, Heldman DR, Karwe MV. Feeding the world today and tomorrow: the importance of food science and technology. Comprehensive Reviews in Food Science and Food Safety 2010;9:572–99.
[11] Slimani N, Deharveng G, Southgate DA, Biessy C, Chajes V, van Bakel MM, Boutron-Ruault MC, McTaggart A, Grioni S, VerkaikKloosterman J, et al. Contribution of highly industrially processed foods to the nutrient intakes and patterns of middle-aged populations in the European Prospective Investigation into Cancer and Nutrition study. Eur J Clin Nutr 2009;63(Suppl 4):S206–25