Are ultra-processed foods a threat to the sustained survival of the planet?
Humans are the only animals clever enough to manufacture their own food, and foolish enough to eat it. Barry Groves (1936–2013)
Many countries have formulated dietary guidelines for their populations. In most cases, these guidelines follow a familiar template with advice to eat or avoid various food groups, food items or food constituents, according to a selective interpretation of unsophisticated nutritional science. This approach has failed to improve public health and has overseen its unparalleled worsening. In response to this failure, overweight and ill-health are increasingly being accepted as a normal state for the human species. Think of any other species for which that is normal.
Enter Brazil.
Brazil has emerged with a holistic approach that looks beyond isolated nutrients but takes into account foods, their sources, combinations, dishes and meals, and the social and cultural dimensions of eating and dietary patterns. The guidelines were made public in 2014.
I’m not going to discuss these guidelines, except for one aspect that has not been properly addressed by prior guidelines — ultra-processed food (UPF). A strong feature of the Brazil guidelines is to avoid UPFs.
Our health has been worsening while our food system has become more industrialised. It’s fair to make a connection, and there is some evidence it is causal (see later). However, that Brazil has had the courage to push-back against transnational industries with eye-watering resources and self-interest with a callous disregard for our health and welbeing is impressive.
What are UPFs?
There’s no exact definition. However, it’s been said to be a bit like pornography — hard to define but you know it when you see it.
One practical way of identifying UPFs is to read the list of ingredients. Look for a high number of ingredients (5 or more) and ingredients that are not familiar and are not used in home cooking (e.g. bulking agents, isolates, hydrogenated oils, colorants, flavour enhancers, sequestrants and humectants).
Some features of UPFs to ponder: Not nutritionally complete but they displace real foods that are nutritious; eaten mindlessly, often while doing something else; hyper-palatable, habit-forming or addictive; don’t signal satiety until they have been overeaten; aggressively marketed, especially to children; attractively packaged (often with misleading health claims); cheap and convenient; often consumed in antisocial situations (in front of TV rather than around a table); decreased diversity in the agricultural sector (industrial mono-cropping) which risks sustainability in the food system; produced by transnational corporations to be uniform worldwide undermining variety in traditional cuisines; production and consumption produces substantial waste and garbage; environmental degradation, pollution and loss of biodiversity.
In the conclusion of the Brazilian guidelines, UPFs are a “serious threat to the sustained survival of the planet”. I presume they mean our survival on the planet. The planet will survive without us.
It is remarkable that cows, producing nutritious food appropriate to our evolutionary biology, are relentlessly under attack, while UPFs do harm to our health, culture and environment and we look the other way.
We should know UPFs are the elephant in the room, but as far as I can tell Brazil is the first country to call them out.
Some UPF science — a randomised controlled trial (RCT)
The rise in obesity and type 2 diabetes has been occurring in step with the industrialisation of our food system. Currently, over half (~60%) of the calories consumed by the adult US population come from UPFs (~70% for children), and there is a clear association with poor health outcomes. However, association does not prove causation, for that a RCT is needed.
Dietary RCTs are notoriously difficult to design and control with free-living participants. To overcome this, 20 participants (10 M/F) were admitted to a metabolic ward for 4 weeks. Here, their diets and lifestyle were under complete control and they could be studied in depth. For 2 weeks, half the participants were given a UPF diet, while the other half consumed an unprocessed or minimally processed diet. At the end of this period, the groups swapped diets for the next 2 weeks.
Meals (3 per day) were varied for interest but matched across diets for total calories, energy density, macronutrients, fibre, sugars and sodium. Snacks appropriate to the diet were available throughout the day.
Crucially, when presented with meals, participants were instructed to eat as much or as little as they wanted. Meals were provided at an amount equivalent to twice each person’s estimated energy requirements, to allow for overeating if desired.
The result was that energy intake reached an astounding ~500 Calories a day higher with the UPF diet compared with the unprocessed diet. For reference, recommended total Calorie intake for males is ~2,500 and females ~2,000 so these additional 500 Calories are striking. Neither the order of the diets, nor gender, had any significant effect. Participants gained weight while on the UPF diet and lost weight when on the unprocessed diet. Participants rated both diets equally pleasant and familiar.
This is the only prospective RCT that I know of. For the first time we see evidence for something inherent to UPFs that promotes excess caloric consumption and weight gain.
Further reading
The Brazil guidelines and the RCT study used the 4-scale NOVA classification system which is based on the nature, extent and purpose of food processing. The four levels are (1) unprocessed or minimally processed (2) processed culinary ingredients (3) processed (4) ultra-processed. Details: The UN Decade of Nutrition, the NOVA food classification and the trouble with ultra-processing
Source and further details of the RCT: Ultra-Processed Diets Cause Excess Calorie Intake and Weight Gain: An Inpatient Randomized Controlled Trial of Ad Libitum Food Intake.
