Highly processed does not necessarily mean unhealthy. This is the message conveyed by nutritionist Hannelore Daniel in an interview with the NZZ. She criticises the fact that highly processed foods – known as UPFs (ultra-processed foods) – have fallen into disrepute and are considered unhealthy per se. According to the scientist, this myth is fundamentally wrong.

According to Daniel, studies linking UPFs to obesity, diabetes or cancer are often based on weak foundations. The main problem is that all these studies refer to the so-called Nova classification, which divides foods into levels 1 (unprocessed) to 4 (highly processed). According to Daniel, the fourth level is particularly problematic, as its criteria are vague and ideologically biased: long lists of ingredients, industrial manufacturing processes, ‘particularly tasty’ – all of these are considered negative across the board.

Arbitrary categorisation

A concrete example shows how arbitrary this classification can be: Ultra-heated milk, industrially processed and made particularly durable through homogenisation, is nevertheless classified in level 1 – i.e. as ‘unprocessed’. A frozen pizza, on the other hand, which contains 18 ingredients, 17 of which can be found in any kitchen, ends up in the fourth level because of a small proportion of modified starch. For Daniel, it is clear that the categorisation is ‘completely unscientific’.

The emeritus professor does not wish to claim that highly processed foods have no problematic effects. Rather, she sees the problem in the fact that these studies are often based on associations. They only show correlations and do not make any statements about whether highly processed foods are actually the cause of a disease. But correlation does not equal causation! Daniel also criticises the fact that the studies are often based on data from old dietary surveys.

She believes that science has a duty to act. Instead of using the term ‘highly processed foods’, researchers should examine the specific ingredients and their effects in detail. Daniel also rejects the general demonisation of all additives. In Europe, 411 food additives are permitted, including simple vitamins, thickeners and colourings. ‘Each of these substances has a different chemical structure, a different effect or is used in different doses,’ says the scientist.

Instead of making sweeping judgements, we need to take a more differentiated view. Food chemist Daniel Wefers takes a similar view. ‘Even with minimally processed foods, you can cook an unhealthy meal – and poison yourself fabulously.’ What's more, many additives have been well researched and are even useful in some cases – for example, to enrich nutrients or extend shelf life.

Consumers also bear responsibility

For Daniel, it is clear that the responsibility does not lie solely with the industry. ‘Of course, companies make products that taste particularly good – just as fashion is designed to appeal to us,’ she says. Ultimately, it comes down to calorie intake.

Her advice: if you don't eat a whole frozen pizza, but put half of it aside, you significantly reduce the calorie, fat and sugar content of your meal – without completely sacrificing enjoyment. Everyone has ‘a knife and fork in their own hands’.

Food from the reactor is also healthy

The call for ‘natural’ foods is just as short-sighted as the blanket rejection of highly processed products. Not everything that is natural is automatically healthy – just as ‘synthetic’ is not inherently dangerous. We need to be more open to innovation and take a more nuanced approach to new technologies and their role in sustainable food production.

A good example are so-called bioreactors, in which food is grown under controlled conditions – sustainably, efficiently and independently of weather, soil or animal husbandry. And: Although these foods are highly processed in the reactor, they are also considered healthy.