What is your idea of ​​processed foods

4-stage system for food according to the degree of processing

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Many dietary recommendations are based on the consideration of energy and nutrient contents or nutrient ratios in food. The focus is only slowly turning to aspects such as food quality and processing. This is due, among other things, to the fact that there are no uniform definitions for differently processed foods across the EU. A Brazilian working group developed a 4-step system that takes into account the degree of processing and can serve as a basis for both scientific studies and consumption recommendations derived from it.

Definitions and assessment options

We fundamentally differentiate between natural or unprocessed and processed or processed foods. So far, however, there is no uniform definition for this. While the term “unprocessed” is understood well and equally by many people, the term “natural” leads to far more differentiated interpretations. Can vegetable oils, bread or flour still be assigned to natural foods? How about natural yogurt and quark? According to the following definition, the examples mentioned are to be assigned to processed foods.

Natural foods

Natural foods are largely unprocessed and untreated. They are also called fresh Labeled food.

Processed foods

Processed foods are industrially processed. The scope of the processing can be very different.

The definition plays for it derived recommendations for consumption play a major role. In addition to the recommendation to consume more low-energy and nutrient-rich foods, it is also often recommended to increase the proportion of unprocessed and fresh products and to reduce the amount of processed products. Many of our recommendations go in this direction. For a varied and practicable diet, however, this cannot be implemented equally well for all foods / groups and repeatedly leads to questions and discussions.

The inadequate definition and delimitation of foods with different degrees of processing also ensures in the science for trouble. On the one hand, there are few studies that even deal with the influence of processed food on people and their health. On the other hand, the few existing studies are hardly comparable, as different definitions and characteristics were used for processed food.

Convenience products

Most of the existing studies examined the influence of convenience products on energy and nutrient intake. These include industrially processed or pre-made products understood [Lexicon of Nutrition], in which processing and preparation steps have already been taken over for the consumer. These are usually partially or ready-to-eat and only make up part of the processed food. Some of the studies are structured very differently and do not come to any comparable results.

Use of additives

Other research has used additives as a criterion for processed foods. Use is regulated across the EU; corresponding products are to be clearly labeled. The clearest result: the intake of additives is significantly higher with frequent consumption of finished products than with the consumption of predominantly fresh, unprocessed food [Mis 2012]. So it is hardly surprising.

Out-of-home consumption

In a few studies, out-of-home consumption was used as a benchmark for the consumption of processed food. Although this definition can probably be questioned the most, quite comparable results have emerged here. Accordingly, frequent out-of-home consumption goes hand in hand with:

  • a higher total energy input
  • a higher total intake of fat
  • a higher total intake of sodium and
  • a lower intake of nutrient-rich foods
[Bow 2004] [Fre 2001] [Kri 2010] [Sat 2004].

These observations are also associated with a higher risk of overweight and obesity [Bes 2010].

The NOVA system for processed foods

The Brazilian research group around Monteiro et al. [Mon 2010] differentiated the term “processed” and considered and located all food groups in a system.

The classification system (NOVA) developed in this way is considered practicable to investigate the influence of industrial food processing on food intake and human health [Mou 2014]. It roughly divides the food into 4 levels (unprocessed to minimally processed, processed ingredients, processed foods and highly processed foods). A further subdivision according to food groups is possible within the 4 levels (see graphic in the member service at the end of the article).

1st group: Unprocessed to minimally processed foods

Untreated and minimally processed foods are the edible parts of plants (seeds, fruits, leaves, stems, roots) or of animals (muscles, innards, eggs, milk). Mushrooms and drinks (water, tea, coffee) also belong to this group. These foods should have the Main part of the daily diet put.

The minimum degree of processing goes back to procedures that remove inedible or undesirable parts; drying, crushing, grinding and dividing; filtering, roasting and cooking as well as alcohol-free fermentation and pasteurization, cooling, freezing and pickling. Vacuum packaging is also one of them.

These processes serve to preserve food and make it storable, i.e. make it edible and keep it. Food of this level is often combined with food of the second and third level.

2nd group: Processed ingredients ("cooking ingredients")

The processed ingredients include vegetable oils, butter, sugar and salt. These ingredients are obtained from foods of the first stage by pressing, refining, chopping, grinding and / or drying. This is intended to achieve the longest possible shelf life.

Ingredients are usually not consumed in isolation or individually, but rather for taste and consistency Added to foods of the first stage in rather small quantities. In combination, it turns into tasty dishes.

3rd group: Processed foods

Processed foods include, for example, freshly baked bread and rolls, aged cheese and canned vegetables, fruit and fish. Basically, these are already combined foods of the first and second stage, which mostly consist of 3-4 ingredients.

They are produced and also by means of various preservation (smoking, curing) or cooking methods as well as fermentation processes in rather smaller quantities individually or in combination consumed.

4th group: Highly processed foods

The fourth level is now probably the largest group of foods available on the market. These are highly processed foods of all kinds. They often consist of individual ingredients and rarely whole foods. This includes ready-made products, most snacks, soft drinks, sweets including chocolate, mixed meat and fish products such as sausage or pre-made frozen meals and instant products. All possible formulations, additives or additives (E-substances as well as flavors) and extracts (e.g. individual types of sugar, milk components, gluten, etc.) are also included.

These products are manufactured to provide long-lasting, ready-to-eat and very tasty products that are also convenient for the consumer and profitable for the manufacturer. Almost all of the advertised foods come from this level. However, these should rather be avoided or only in small amounts to consume.

From this, Brazil has drawn up the following national consumption recommendations:

  1. Level 1 foods are the basis of daily nutrition.
  2. Level 2 foods serve as level 1 ingredients in small quantities.
  3. Level 3 foods are combined with Level 1 or 2 in limited quantities.
  4. Avoid level 4 foods.

Tip: In order to assign food according to this system, corresponding products can be created with the app #NUTRISCORE can be scanned. This is followed by information on nutritional values ​​and possible critical ingredients as well as the classification of the product according to the Nutriscore and NOVA system. The app is available for Windows, Android and iOS.

Degree of processing and effects on humans

"There are concerns about both sides - what is added and how it affects your health and what is removed and how it affects your health," said Lynn Grieger once. This is now increasingly being confirmed in scientific studies. Nevertheless, most of the effects listed below are initially only observations that need to be proven in further studies.

saturation

The saturation effect decreases as the degree of processing increases. This in turn increases the risk of frequent snacking - one of the main causes of a positive energy balance.

Supply of vitamins, minerals and secondary plant substances

On the other hand, it has long been known that every processing step that is carried out with heat, pressure, oxygen, etc., potentially reduces the content of sensitive vitamins and phytochemicals. In particular, the removal of certain unwanted food components can seriously impair the mineral content.

Supply of fiber

Heavily processed foods have a lower average fiber content [Cor 2018]. The proportion of indigestible carbohydrates in fresh, whole apples is greater than in applesauce and here again higher than in apple juice. This also reduces the saturation effect.

Proportion of sugar and fat

The sugar, fat and salt content is particularly high in finished products. This increases the energy supply.

Energy content

Due to the lower content of filling ingredients such as dietary fiber, but also of liquid and volume, there is a risk that the higher the processing level, the energy supply increases in order to achieve the same saturation. This in turn could lead to overweight and obesity [Hal 2019].

Absorption of additives

Industrially manufactured products increase the absorption of undesirable additives (e.g. sweeteners, preservatives, colorings, phosphates, etc.) [Hei 2017].

Absorption of unwanted accompanying substances (e.g. in packaging, etc.)

An increased uptake of plasticizers (goods packed in plastic) [Mao 2015], heavy metals (foreign, dried products) or other pollutants that arise during the manufacturing process [DeJ 2014] is also possible. Examples are trans fatty acids, acrylamide and also oxidized cholesterol.

One in JAMA (Journal of the American Medical Association) Research published in 2019 showed higher mortality rates in a diet with a high percentage of highly processed foods [Sch 2019]. Others observed a higher risk of cancer [Fio 2018]. However, this evidence has yet to be confirmed in further research.

One can only speculate about the exact mechanisms. However, it is quite conceivable that the consumption of predominantly fresh food is more beneficial for health than a high proportion of finished products.

Conclusion for nutritional practice

Overall, it becomes clear that due to a lack of uniform definitions and inconsistent or incomplete studies (so far) no evidence-based statement the influence of the degree of processing of food on the supply of energy and nutrients, on body weight and thus also on health can be determined. Without this scientific basis, related consumption recommendations are always vulnerable. Nevertheless, in addition to the hypotheses mentioned, there are at least two further arguments for restricting the consumption of level 4 foods in particular.

For one thing, it affects them Control what I eat. Only when I know what I am eating can I draw conclusions for myself and my health. This is no longer always possible with level 4 foods.

On the other hand, I keep a more natural taste. There are also big differences in terms of quality and taste when it comes to fresh food and ingredients. Nevertheless, the consumption of artificial flavors is lower. This can also have a positive effect on my taste preferences.

Well it sure is not necessary, on all processed products of level 4 always to renounce. Occasional out-of-home and fast food consumption is rather unproblematic with a long-term balanced diet. For the beginning it can be helpful to have the proportion of to increase the use of fresh products in daily food.

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