Take home message

• There are concerns about our eating habits. In the 1950s, there was concern around eating animal fat. We are more than 60 years on.
• After the food industry hand in hand with science has convinced us for a diet with less fat and salt, we need to change course again: we are now eating too many ‘ultra-processed’, sugar-rich foods and drinks. With major consequences for the health of populations worldwide.

Ready-made meals

Ultra-processed food (UPF) are the compound packages and sauces you buy ready-made in the supermarket. Not so much the tray of pre-cut and mixed salads, but the ready-to-eat meals; add a little water, just fry some lean, roast chicken legs and dinner is on the table in 10 minutes. Add to that the sugary, energy-drinks and a new problem is created: refined sugars and processed vegetable oil.

We suffer of non-communicable diseases (NCDs), such as being too fat, especially abdominal fat, permanently low levels of inflammation, fatty liver, cardiovascular disease, as well as dementia and autism. Diseases of affluence, which industry was all too keen to make us believe was due to lack of exercise rather than the composition of their food. They preferred to see the slogan, that by moving more, you burned more calories and those who got too fat were really to blame. Due to the long arms of the industry, even Michelle Obama, in her time as first lady, could do no more than urge people to ‘move more’. She was not allowed to go further.

Ultra-processed or proper cooked meal by yourself?

In th US, a trial with volunteers was conducted (Hall et al., 2019). Under controlled conditions, slightly overweight adults (31 years, BMI = 27), were followed up for four weeks. They were presented with two types of diets, each for a fortnight: (1) UPF-based (read: ultra-processed) and (2) ‘normal’ staple foods (read: unprocessed). Subjects were asked to eat three meals from the point of view, eat so much or so little that you feel fed up. So, your stomach and sense of satiety determined how much you ended up eating.

Getting the two types of food to be completely similar in composition was already quit complicated, and Hall et al, (2019) write: ‘although we tried to match various nutritional parameters between the diets, the ultra-processed and unprocessed meals differed significantly in the ratio of added to total sugar (54% vs. 1%, respectively), indigestible to total fibre (16% vs. 77%), saturated to total fat (34% vs. 19%), and the ratio of omega-6 to omega-3 fatty acids (11:1 vs. 5:1).’ In other words, ultra-processed foods are characterised by the addition of all kinds and types of sugars, little to no ballast substances (fibre), high saturated fat content and a strong n6/n3 imbalance. How the food industry manages this, you sometimes don’t understand, since the meal cost for the daily 2,000 kcal for the ultra-processed food was only 2/3 of that of the unprocessed food. So, this multi-billion dollar industry provides food at a price, for which yourself cannot or will not cook anymore. The question is who or what groups or what part of nature pays the price for it.

How ultra-processed food impacts your health

First, it makes you eat more. During the ultra-processed food period, volunteers took in almost 500 cal/day more than during the unprocessed food period (Hall et al., 2019). The extra energy came from higher intake of sugars and fat. Ultra-processed food has a higher energy density, i.e. contains many calories per bite. You should not confuse this with the concept of nutrient density, which is a characteristic of how many minerals, trace elements and secondary plant metabolites (such as antioxidants) are present in food. Energy-dense food is empty, and you mainly take in calories. Incidentally, what is greatly increased in the ultra-processed diet is the salt intake, a characteristic considered unfavourable.

In the US, the portions one buys, be it hamburgers, sodas or chicken nuggets, have been getting bigger and bigger over the years. Perhaps this confirms the view, that such ultra-processed foods no longer provide or do not provide sufficient satiety and, as a result, people tend to take in more food; at least more than they need to maintain weight or function. The group that ate ultra-processed food also ate faster; in a shorter time, they worked down more calories. Apparently, you go a bit gulping from this kind of food.

Second: in the two weeks, when people took ultra-processed food, they gained weight: almost 1 kg (900 g) in weight, while the opposite occurred (-1 kg) during the period of unprocessed food. There was a strong correlation with the number of calories ingested by each volunteer: the more, the fatter they became. Further, you see an increase in fat mass of about 0.4 kg, but also in lean mass (+0.5 kg), (Fig. 1). On a body scan, no difference in fatty liver could be detected.

Third: There were two hormones in the blood that express something about ‘feeling satiated’, (1) hormone PYY is a measure of whether ‘you feel hungry’ and (2) the hormone ghrelin is known as the ‘hunger hormone’. Both were lower when unprocessed food was eaten. In other words, less cravings and less feeling of hunger. Important blood levels surrounding Type-2 diabetes were lower, namely glucose (‘fasting glucose’) and the hormone insulin, which regulates blood glucose levels. In conclusion, a degree of addiction occurs with the consumption of ultra-processed food (see also: Monteiro et al., 2022), giving rise to overconsumption, feelings of hunger and gradual fattening with all the immunological problems that come with it.

Third: There were two hormones in the blood that express something about ‘feeling satiated’, (1) hormone PYY is a measure of whether ‘you feel hungry’ and (2) the hormone ghrelin is known as the ‘hunger hormone’. Both were lower when unprocessed food was eaten. In other words, less cravings and less feeling of hunger. Important blood levels surrounding Type-2 diabetes were lower, namely glucose (‘fasting glucose’) and the hormone insulin, which regulates blood glucose levels.

In conclusion, a degree of addiction occurs with the consumption of ultra-processed food (see also: Monteiro et al., 2022), giving rise to overconsumption, feelings of hunger and gradual fattening with all the immunological problems that come with it.

Watch out for the generations to come

A second study examines the effects on the unborn child. Pregnant mothers scored their diet with emphasis on the amount of ultra-processed food. This is a Dutch study conducted through Erasmus Medical Centre (Smit et al., 2022). Using 3-dimensional ultrasound, the length of the unborn child is measured in 700 pregnant women. There is a wide range of the number of calories (energy) absorbed by mothers from UPF: 16% to 88%. After adjusting for a variety of factors, the model calculated a significant relationship between UPF intake and infant size. However, this relationship was negative: the more UPF, the smaller the baby. In models, you can include or exclude all kinds of factors. When you move from one model to another, you can see whether certain factors really have an impact on the outcome. Interestingly, in a modified model, which further corrected for vitamin intake (especially the B vitamins) plus also Zinc, the correlation disappeared. This implies, that these vitamins matter for the outcome, and that you correct (partly explain) the negative outcome of UPF, as it were, by the difference in vitamin intake. To estimate the effects of diet, they compared the study with other pre-natal research: ‘Compared with previous research on maternal lifestyle, UPF energy intake in pregnancy is comparable in terms of negative effect size to maternal smoking more than 10 cigarettes a day.’

Maybe strange enough, those slightly smaller babies apparently later grow into huge fatties.

Weston A. Price

Earlier, but never enough, we have written here about the impressive research work of dentist/ researcher Weston A. Price. Price wanted to know, how people remained healthy through the generations without the presence of doctors and dentists. After 10 years of research on the lifestyles of more than 15 traditionally living natural populations, his conclusion was that these people stayed healthy by eating unprocessed (raw) foods, with an emphasis on fermented products. People loved animal products, but there was usually not much of them, except for the Eskimos. There was a focus on special nutrition during pregnancy, which can be summarised by eating special products rich in omega-3 fatty acids and fat-soluble vitamins, like A and D.

The diet and lifestyle of the natural populations can be summarised by eating local, fresh, home-made products, foods with a high nutrient-density, rich in pro- and post-biotics after the food was fermented. Problematic pregnancies and non-communicable diseases were unknown back then. Less than 100 years later, much of the world’s population is saddled with dead food, compounded and cobbled together from all over the world, refined, reprocessed and profit-driven by companies, which sell inferior food. Not ‘nutrient-density’ based on natural food, but ‘energy-density’ is a feature of the UPF, not a living product rich in bacteria and nutrients, but a stripped-down, composed, compounded, dead product full of all kinds of hidden sugars.

Monteiro et al. (2022) characterise the UPF as follows: ‘Common ingredients of ultra-processed foods are cheap protein sources, such as soy and other plant extracts; modified starches and sugars such as maltodextrin, fructose containing corn syrup and invert sugar; and modified vegetable oils. Such mixtures by themselves would evoke unpalatability or even disgust, which must be compensated by adding flavourings, colourings as well as flavour enhancers and many other additives. All these additives have not been checked for addictive potential, or their impact on brain functions. Some additives are deliberately used by manufacturers to induce a ‘violent desire for more’. Added flavourings can trigger overeating and ‘eating to eat’ (‘eating addiction’), resulting in weight gain. Normally, there is a physiological brake on overeating, but this feedback is taken over and switched off by such foods.’

Literature

• Hall, K. D., Ayuketah, A., Brychta, R., Cai, H., Cassimatis, T., Chen, K. Y., … & Zhou, M. (2019). Ultra-processed diets cause excess calorie intake and weight gain: an inpatient randomized controlled trial of ad libitum food intake. Cell metabolism, 30(1), 67-77.
• Monteiro, C. A., & Cannon, G. (2022). The foods that are addictive. Addiction.
• Smit, A. J., Hojeij, B., Rousian, M., Schoenmakers, S., Willemsen, S. P., Steegers-Theunissen, R. P., & van Rossem, L. (2022). A high periconceptional maternal ultra-processed food consumption impairs embryonic growth: The Rotterdam periconceptional cohort. Clinical Nutrition.

Photo: cutting open a Parmesan cheese. Cheese should not be confused with UPF. Cheese making involves ‘natural processing’, not industrial processing, as expressed in this article.