Why Should You Avoid Ultra-Processed Foods?

  • Walija Ansari Master's degree, MSc Oral Sciences, University of Glasgow, UK

Enhancing processed foods with vital nutrients like vitamins D and B, calcium, protein, and fibres can benefit health. Still, it's crucial to be cautious about certain food processing methods that may be linked to negative health outcomes, especially in products lacking nutrients and containing high levels of added sugars, salts, and unhealthy fats.


What is processed food?

Processed food is any food that has been altered from its natural state.

Food processing can be as simple as:

  • Freezing
  • Canning
  • Cooking

What falls under the category of processed foods?

Examples of typical processed foods include:

  • Cheese
  • Breakfast cereals
  • Canned vegetables
  • Drinks, such as milk or soft drinks
  • Meat products, such as sausage, bacon, ham, salami, and paté
  • Biscuits and cakes
  • Bread
  • Microwave meals or ready meals
  • Savoury snacks, such as chips, pies, and pastries

Is there any advantage in consuming processed food?

Food technologies are commonly developed to preserve the qualities of food, and food processing can have beneficial effects, including increased shelf life and better absorption of nutrients.1 

However, not all processed foods are bad for you. Some foods need processing to make them safe; for example, milk is pasteurised to remove harmful bacteria, while seeds are pressed to produce oil. Wholemeal bread, high-fibre breakfast cereals, and certain lower-fat yoghurt can be essential components of healthy nutrition.

Moreover, certain fortified foods offer vital nutrients that might be challenging to obtain in a busy household or one with budget constraints.

This article provides insights into processed foods, categorising them and investigating their potential health impacts. It introduces the NOVA classification system, which classifies processed foods into four groups according to their processing level. These categories include everything from unprocessed or minimally processed foods to processed and ultra-processed foods, often containing additives and artificial components. The article emphasises the health implications of ultra-processed foods, highlighting their connection to weight gain, obesity, and chronic conditions, including diabetes.

Why are some processed foods less healthy?

Food processing can also have negative impacts, such as high levels of artificial additives and the loss of nutrients. In the same way, the food content of fibres, vitamins, sodium, and minerals can be affected by industrial processing. Furthermore, the industry also uses food technology to manipulate the taste and texture of the food, increasing its consumption.1

In 2009, researchers from the University of São Paulo, Brazil, introduced the NOVA classification system, which gained widespread recognition for categorising processed foods according to the degree to which a food is processed and the intended purpose behind these modifications.

The four categories of processing include:

Unprocessed or minimally processed foods

Unprocessed foods include parts of plants and animals that are edible in their natural state. Minimally processed foods are foods that have undergone slight alterations to improve storage, preparation, and consumption. This degree of food processing does not significantly change its nutrient composition. Examples include the removal of non-edible parts, washing, refrigeration, fermentation, pasteurisation, grinding, vacuum packaging, and freezing. This type of processing ensures the food’s extended shelf life while remaining safe for consumption. Many vegetables, fresh fruits, nuts, whole grains, milk, plain yoghurt without additional ingredients, coffee, and tea belong to this group.

Processed culinary ingredients

Within this category, you'll find kitchen ingredients derived from minimally processed foods through methods like grinding, milling, pressing, or refining. These are typically not consumed independently but serve as components for food preparation. Some examples include plant oils, vinegar made by the acetic fermentation of wine, seeds, nuts, honey extracted from honeycombs, and others.

Processed foods

In this group, the processing increases the shelf life of foods or improves the flavour and texture. Processed foods are derived from either of the two preceding categories, with the addition of salt, sugar, and/or fat. Some cheeses, canned fish, and canned vegetables or fruits are examples of this category. Typically, these foods are made using 2-3 ingredients and can be readily consumed without additional preparation.

Ultra-processed foods

Foods that go a few steps further are considered ultra-processed, also known as highly processed. Instead of just adding salt, sugar, or fat, these products also contain artificial colours, sweeteners, thickeners, preservatives, and emulsifiers that enhance their shelf stability, texture, and tastiness. They have undergone several stages of processing, using multiple ingredients, and are often manufactured on a massive scale with low-cost ingredients, making them inexpensive and highly profitable. It is thought that all of these additions add taste and flavour so that people consume them excessively and purchase more. These foods are usually ready to consume without needing further preparation.

Some examples of ultra-processed foods include:

  • Sweetened breakfast cereals
  • Chicken nuggets
  • Hot dogs
  • Sugary drinks
  • Chips
  • Packaged soups 
  • Some frozen dinners
  • Cookies
  • Some crackers

According to observational studies, ultra-processed food consumption is consistently linked to an increased risk of weight gain among both adults and children and an increased risk of health issues related to excess body fat in adults.2

What are the drawbacks of processed and ultra-processed food?

There are a few reasons to avoid the consumption of processed foods, such as:

  • Loss of vitamins, e.g., tinned vegetables
  • Lower levels of fibre, particularly in white bread, white rice, and pasta
  • Highly Processed foods have a high glycemic index and tend to be digested rapidly, causing substantial fluctuations in blood sugar, which can be particularly disadvantageous for people with type 2 diabetes

Why are ultra-processed foods bad for you?

For some time now, experts have been aware of the connection between consuming highly processed foods and health. Ultra-processed foods typically have excessive amounts of sugar, salt, and unhealthy fats. Consuming them can limit the room in our diets for healthier, more nutritious foods.

Moreover, the use of ultra-processed foods is growing in diets worldwide, affecting even infants, children, and teenagers. This global shift is linked to an increase in overweight and obesity, metabolic syndrome, and other chronic conditions like cardiovascular diseases, hypertension, and type 2 diabetes.3 

In addition, research suggests that the consumption of ultra-processed foods may elevate the risk of cancer due to factors like their contribution to obesity and exposure to potentially cancer-causing substances, such as certain food additives and harmful compounds produced during food processing, like trans fats and acrylamides.4 

Moreover, several studies have found a link between eating more ultra-processed foods and a higher risk of dementia, further emphasising the disadvantages associated with their consumption.5,6 

Interpreting the ingredients list on a food label

Being aware of the ingredients included in a food is generally good practice for everyone, but especially for those with diabetes, allergies, intolerances, or digestive problems. Additives such as artificial colours may cause allergic reactions in some individuals. For those with sensitive stomachs, thickeners may cause mild bloating or diarrhoea. Usually, the longer the list of ingredients, the more highly processed the food is. However, an ingredient with a long chemical name is not necessarily harmful.

When you buy food products, consider the following on a food package:

  1. The ingredients that weigh the most will be listed first, while those that weigh the least will be listed last
  2. Sugar and salts may be listed with different names. Common alternative terms for sugar include corn syrup, high-fructose corn syrup, cane sugar, coconut sugar, molasses, dextrose, agave nectar, evaporated cane juice, or turbinado sugar. Alternative terms for sodium include disodium phosphate and monosodium glutamate
  3. Ultra-processed foods may contain several food additives, such as artificial colours, preservatives, or flavours. Some of their ingredients might seem less familiar. Preservatives are often added to ensure safety by preventing the growth of bacteria and mould. Names you can see on the labels include:
    • Colours artificial FD&C Yellow No. 6 or natural beta-carotene
    • Preservatives: sodium benzoate, potassium sorbate, ascorbic acid, and tocopherols
    • Thickeners: xanthan gum, guar gum, pectin, and carrageenan
    • Emulsifiers: monoglycerides and lecithin

Commonly consumed foods are often fortified by adding vitamins and minerals to increase their nutritional value. It is a safe, proven, and economical approach to improving diets and preventing and controling micronutrient deficiencies.7 Examples of included nutrients are vitamin C (ascorbic acid), vitamin D, B vitamins (riboflavin, niacin, niacinamide, folate, or folic acid), amino acids to amplify protein content (L-tryptophan, L-lysine, L-leucine, and L-methionine), beta carotene or iron (ferrous sulphate).

Should I cut down on ultra-processed foods?

Given that ultra-processed foods tend to be more calorie-dense than nutrient-dense taking care to limit their intake is unlikely to pose extra risks or harm and is more likely to result in better health.

Therefore, while we are looking forward to new research, scientists suggest limiting the consumption of ultra-processed food, which is more likely to result in benefits than harm.2


Processed food refers to any food that has undergone alterations from its natural state, which can be as simple as freezing, canning, or cooking. Food technologies aim to maintain food quality while simultaneously enhancing factors like shelf life and nutrient absorption. Notably, not all processed foods are detrimental; some are necessary for safety or to provide essential nutrients.

Yet, food processing can also have drawbacks, such as high levels of additives and nutrient loss. Ultra-processed foods often contain additives, preservatives, and artificial components, contributing to their high level of processing. These products often feature excessive amounts of sugar, salt, and unhealthy fats, crowding out nutritious foods in our diets.

Ultra-processed foods have been linked to health issues, including weight gain, obesity, and chronic conditions like diabetes. Experts suggest limiting the consumption of ultra-processed foods to promote better health. While we await further research, taking precautionary advice to reduce their intake is more likely to bring about health benefits than harm.


  1. nhs.uk [Internet]. 2022 [cited 2023 Nov 9]. Eating processed foods. Available from: https://www.nhs.uk/live-well/eat-well/how-to-eat-a-balanced-diet/what-are-processed-foods/
  2. Avenue 677 Huntington, Boston, Ma 02115. The Nutrition Source. 2019 [cited 2023 Nov 9]. Processed foods and health. Available from: https://www.hsph.harvard.edu/nutritionsource/processed-foods/
  3. Diabetes. 2022 [cited 2023 Nov 9]. Available from: https://www.diabetes.co.uk/food/processed-foods.html
  4. de Araújo TP, de Moraes MM, Afonso C, Santos C, Rodrigues SSP. Food processing: comparison of different food classification systems. Nutrients [Internet]. 2022 Feb 9 [cited 2023 Nov 6];14(4):729. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8877594/
  5. Crimarco A, Landry MJ, Gardner CD. Ultra-processed foods, weight gain, and co-morbidity risk. Curr Obes Rep [Internet]. 2022 [cited 2023 Nov 7];11(3):80–92. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8532572/
  6. Popkin BM, Ng SW. The nutrition transition to a stage of high obesity and noncommunicable disease prevalence dominated by ultra‐processed foods is not inevitable. Obesity Reviews [Internet]. 2022 Jan [cited 2023 Nov 8];23(1). Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8639733/
  7. Kliemann N, Al Nahas A, Vamos EP, Touvier M, Kesse-Guyot E, Gunter MJ, et al. Ultra-processed foods and cancer risk: from global food systems to individual exposures and mechanisms. Br J Cancer [Internet]. 2022 Jul 1 [cited 2023 Nov 7];127(1):14–20. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9276654/
  8. Li H, Li S, Yang H, Zhang Y, Zhang S, Ma Y, et al. Association of ultra-processed food consumption with risk of dementia: a prospective cohort study. Neurology. 2022 Sep 6;99(10):e1056–66. Available from: https://pubmed.ncbi.nlm.nih.gov/36219796/
  9. Gomes Gonçalves N, Vidal Ferreira N, Khandpur N, Martinez Steele E, Bertazzi Levy R, Andrade Lotufo P, et al. Association between consumption of ultraprocessed foods and cognitive decline. JAMA Neurol. 2023 Feb 1;80(2):142–50. Available from: https://pubmed.ncbi.nlm.nih.gov/36469335/
  10. Olson R, Gavin-Smith B, Ferraboschi C, Kraemer K. Food fortification: the advantages, disadvantages and lessons from sight and life programs. Nutrients [Internet]. 2021 Mar 29 [cited 2023 Nov 9];13(4):1118. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8066912/
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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