What is processed food and how does it affect our health?
What is processed food?
For most people, the term processed food has a negative connotation, but the fact is that it isn’t always the processing itself that is unhealthy. If we take the correct meaning of the word, then the processing of a food begins as soon as we affect it or change it in some way. Technically speaking, therefore, a tomato that has been sliced, broccoli that has been boiled and fish that has been cooked in an oven have all been processed in some way.
What we normally mean when we talk about processed food are foods that have been exposed to some sort of industrial processing. This includes products such as breakfast cereals and sweets for example, as well as healthy foods like nut butter and plant-based drinks.
Unprocessed, processed and ultra-processed food
Many major organisations like the UN and WHO currently apply the NOVA classification – a four-grade scale created by a group of Brazilian researchers for classifying processed food. This scale divides foods into four categories on the basis of how much they have been processed.
1. Unprocessed or minimally processed foods
- Fruits, vegetables, root vegetables or other edible parts of plants in their entirety
- Food from animals in a nearly natural state, such as meat, eggs and milk
2. Processed culinary ingredients (obtained from Group 1)
- This includes butter, sugar, salt, honey, syrup and cooking oils such as rapeseed oil and olive oil
3. Processed foods (combination of Group 1 and Group 2)
- Canned vegetables and legumes
- Tinned fish
- Certain types of processed animal foods such as hams, bacon, smoked fish
- Freshly baked bread
4. Ultra-processed foods (food typically made by a series of industrial techniques, containing at least 5 ingredients and different types of additives)
- Carbonated and sugary drinks
- Sweet, fatty and salty snacks
- Candies and pastries
- Mass-produced/packaged breads and buns
- Sweetened breakfast ‘cereals’ and fruit yoghurt
- Energy drinks
- Ready meals
- Fish fingers, sausages and other semi-finished foods
- Powdered soups and replacement meals
It is also worth mentioning that although the NOVA classification is in widespread use, it has come under criticism from a number of researchers who believe that many foods on the list have been miscategorised. One example that is often cited is unflavoured yoghurt, which is classified as a minimally processed food when it is in fact a food that has undergone significant processing.
Ingredients or processing – which is unhealthy?
In most cases, it is the actual nutritional content, not the processing itself, which determines how unhealthy food is. This is evidenced not least by all those processed foods that are in fact good for our health – oats, pre-cooked beans and seeds, preserved fish etc. Yet it should also be noted that certain processed food, and almost all ultra-processed food, is low in both nutrition and fibre. It is also common to add large amounts of additives, sugars, salt and/or fat to this type of product. Ultra-processed food is therefore often high in calories, sugar, additives and bad fats, and low in nutrition – in other words, not a great combination for our health.
The general consensus that processed food is automatically unhealthy is nevertheless misleading if you don’t take into account several other factors, such as nutritional and fibre content. When we talk about beneficial and non-beneficial foods, we should start by differentiating between ultra-processed and processed foods as there is a big difference between these categories. Moreover, our primary tool for determining how beneficial a food is, should be the list of ingredients and nutritional declaration on the product.
People who eat processed food eat more calories
A study by the American National Institute of Health produced interesting results related to eating habits and the consumption of processed food. The study compared two groups of students, one of which ate a diet of unprocessed and minimally processed food. The second group ate a diet of processed and ultra-processed food. The participants in the study were given three meals a day and also had free access to snacks throughout the day. For each meal, participants were offered double the amount of calories they were estimated to need and instructed to listen to their gut and stop eating when they felt full.
The results showed that the participants who ate the ultra-processed food consumed on average around 500 calories more per day than those who ate the minimally processed food. The intake of carbohydrates and fat was higher among those who ate the processed food, but the intake of protein was roughly the same in both groups.
Other risks and health impacts associated with processed food
- Processed meats, such as bacon, sausages and hams, can increase your risk of colon and rectal cancer, type 2 diabetes, obesity and coronary heart disease. The Swedish National Food Agency (Livsmedelsverket) recommends limiting your intake of red meat to a maximum of 500 g per week.
- Several studies have shown a correlation between consuming ultra-processed fast food/junk food and high overall energy intake, weight gain and insulin resistance.
- Consuming drinks with added sugar can increase your risk of type 2 diabetes. There has also shown to be a connection with childhood obesity, cardiovascular diseases, inflammation, high blood pressure, renal failure etc.
- Ultra-processed food has also been linked to excess weight, obesity, metabolic syndrome, high levels of fat in the blood, cancers and high blood pressure.
- A typical Western diet comprising a high proportion of ultra-processed food seems to be associated with lower quality of life and mental health issues such as depression and anxiety among adults.
Nearly all foods classified as ultra-processed should be avoided as far as possible. This is both for the sake of your health and because these foods are largely made up of empty calories rather than containing high levels of nutrition or fibre. All the same, we shouldn’t get too hung up on definitions, and instead should rely on the nutritional and not least, common sense when choosing what to feed our bodies with. If you need advice on how to eat more healthily, you can find more reading material in the articles below.
Canella DS, Levy RB, Martins APB, Claro RM, Moubarac J-C, Baraldi LG, m.fl. Ultra-Processed Food Products and Obesity in Brazilian Households (2008–2009). PLOS ONE. mars 2014;9(3):e92752.
Fiolet T, Srour B, Sellem L, Kesse-Guyot E, Allès B, Méjean C, m.fl. Consumption of ultra-processed foods and cancer risk: results from NutriNet-Santé prospective cohort. BMJ. 14 februari 2018;360:k322.
Juul F, Hemmingsson E. Trends in consumption of ultra-processed foods and obesity in Sweden between 1960 and 2010. Public Health Nutr. december 2015;18(17):3096–107.
Juul F, Martinez-Steele E, Parekh N, Monteiro CA, Chang VW. Ultra-processed food consumption and excess weight among US adults. Br J Nutr. juli 2018;120(1):90–100.
Mendonça R de D, Pimenta AM, Gea A, de la Fuente-Arrillaga C, MartinezGonzalez MA, Lopes ACS, m.fl. Ultraprocessed food consumption and risk of overweight and obesity: the University of Navarra Follow-Up (SUN) cohort study. Am J Clin Nutr. 01 november 2016;104(5):1433–40.
Nardocci M, Leclerc B-S, Louzada M-L, Monteiro CA, Batal M, Moubarac J-C. Consumption of ultra-processed foods and obesity in Canada. Can J Public Health Rev Can Sante Publique. februari 2019;110(1):4–14.
Poti JM, Braga B, Qin B. Ultra-processed Food Intake and Obesity: What Really Matters for Health – Processing or Nutrient Content? Curr Obes Rep. december 2017;6(4):420–31.
Silva FM, Giatti L, Figueiredo RC de, Molina M del CB, Cardoso L de O, Duncan BB, m.fl. Consumption of ultra-processed food and obesity: cross sectional results 34 from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) cohort (2008–2010). Public Health Nutr. augusti 2018;21(12):2271–9.