Food processing: whats the problem?
Food processing simply means changing a food from its natural form. Unless you are eating a vegetable you have harvested straight from the ground in your garden, you are probably eating food that has been processed to some degree.
The act of processing food itself does not make a food bad nor does eating a food completely unprocessed make it good for you- some foods need to be processed to be healthy for us to eat. Food processing techniques such as fermenting, freezing, pasteurization and drying have been used for thousands of years to preserve, increase food safety and enhance nutritional benefits. As manufacturing capabilities have increased, processing of food has provided convenience, availability and improved taste, however, this has come at a cost of decreased nutritional benefit.
'over-reliance on processed foods, especially energy dense foods high in sugar, fat and salt, is gradually displacing home-prepared meals and consumption of fresh fruit and vegetables in typical diets'- FAO, 2015
Addition of flavourings, colours, preservatives, refined sugars, thickeners, emulsifiers have fuelled an epidemic of addiction to ultra-processed foods. Food manufactures use these additives to manipulate the rewards systems in our brains making these food more tasty, visibly more pleasing and addictive. In addition, use of these additives make foods highly profitable for food manufacturers making them richer and further fuelling the processing fire.
Around 50-60% of our diet is ultra-processed.. just let that sink in
NOVA classifies all foods into four groups;
Unprocessed and minimally processed foods
This group includes the edible parts of plants (fruits, leaves, seeds, roots, stems) and edible parts of animals (muscle, organs,eggs, milk) as well as fungi, algae and water.
Minimally processing methods include removal of inedible parts, drying, grinding, filtering, fermentation, pasteurisation, freezing, vacuum packing. These methods are used to preserve natural foods. E.g Packaged vegetables, frozen fruit and vegetables, dried fruits, filtered water
Processed culinary ingredients
This group includes oils, butter, sugar, lard, salt, dried herbs and spices are usually made by processes of pressing, drying, milling and grinding. These foods are usually used to prepare, season and cook fresh ingredients. Alone, they are nutritionally unbalanced which is why they are rarely consumed alone.
Processed foods
These are food made by adding group 2 foods to group 1 and include canned foods such as vegetables, pulses in brine, fruits in syrup, tinned fish in oils as well as cured, smoked, salted, pickled animal foods and fish. Freshly baked breads and some cheese that have salt added are include in this category too however the processing of these rarely impacts our health negatively.
Processed foods usually retained the basic identify and constituents of the original food, they have been modified by are still recognisable. When excessive oils, sugar or salt are added they can become nutritionally unbalanced and so should be used sparingly.
Ultra-processed foods
Foods included in this category are those that have undergone extensive processing that involves numerous steps. Processing includes fractioning cheap whole foods such as corn, wheat, soya, cane or beet into substances or pureeing animal carcasses. These fractioned foods then undergo several chemical modifications with addition of colours, flavours, thickeners and emulsifiers which makes then hyper palatable (attractive in all ways). These food rarely resemble to original food source.
Ultraprocessed foods include confectionary, cereals, dairy products containing additives, preserves, sauces, pre-prepared animal products (sausages/burgers) etc.
Identifying ultra-processed foods
Food manufacturers do not have to state the extent of food processing on product labels but it is worth having a look at the ingredient labels as these must be added by law and give an indication of the extent of processing. What to look for:
Minimal ingredients- generally the fewer ingredients the more closely it represents the whole food source
Ingredients you would store in your cupboard or that are used in a kitchen- if you don’t recognise an ingredients its likely that it’s a chemical additive.
Does it contain any food classified in the ultra-processed food group- emulsifiers, thickeners, flavours, colouring, artificial sweeteners, anti-foaming agents, bulking agent.
Ultra-processed foods will usually be named at the end of ingredients list.
Once upon a time, we spent days hunting and gathering food, now, we drive to the supermarket and are presented with isles and isles of pre-made, pre-packaged, cheap foods. While the increase in food processing have increased availability and convenience it has also driven the 'obesity epidemic' declared by the World Health Organisation (WHO). In 2016, over 39% of the worlds adult population were overweight and that percentage has been forecasted to rise another 33% by 2030. (Jackson et al., 2020). With an attempt to reverse the epidemic, food manufacturers increased processing to remove salts, sugars and fats from products- the substances thought to lead rising obesity levels. These foods were replaced by chemical alternatives and products were labelled 'lower calorie' 'low fat' - resembling their whole foods source even less. As well as decreasing the nutritional value of foods we have increased the chemical contents of food which our bodies are not made to be able to digest.
Lets look at the affect on our bodies. For one- These chemical substances are confusing for our gut microbes, the work force behind our digestion. These are not substances that our gut microbes are familiar with in nature and so we do not have the tools to break these down, they are identified as foreign to our bodies. So what happens when a foreign substance enters our system? Just like bacterial infections and viruses they aggravate our immune system leading to inflammation. This chronic inflammation promotes obesity. And secondly, not only do these ultra-processed foods contains chemical additives they no longer contain the nutritional benefits of the source whole foods- 'low fat- fats have been removed' 'low calorie- tends to lose the fibre, fat and proteins' and so we are no longer fuelling our bodies with the necessary nutrients leading to nutritional deficiency, slowed digestion (inability to breakdown foods= obesity) and in the long term failure of keys systems - liver- detoxification, cardiovascular- blood and oxygen circulation, nervous- brain and muscle function etc.
So while not all processing is bad for us and actually can be beneficial, my advice is to stick to whole foods and minimally processed foods and reducing the intake of processed and ultra-processed foods. While 'low calorie' 'low fat' may be appealing for weight loss these foods can actually be more harmful that good in the long-term so do future you a favour and eat a whole food based diet.
References
Jackson, S.E., Llewellyn, C.H. and Smith, L. (2020). The obesity epidemic – Nature via nurture: A narrative review of high-income countries. SAGE Open Medicine, [online] 8, p.205031212091826. doi:10.1177/2050312120918265.
Monteiro, C., Cannon, G., Lawrence, M., Laura Da Costa Louzada, M. and Machado, P. (2019). Ultra-processed foods, diet quality, and health using the NOVA classification system Prepared by. [online] Available at: https://www.fao.org/3/ca5644en/ca5644en.pdf.