Most people are aware that some foods are rated as healthy; others are not. In Australia, the healthy foods that can meet all your nutritional needs are arranged into the five food groups:
- vegetables
- fruit
- grains (predominantly wholegrains)
- meat, fish, poultry, eggs, legumes, nuts, seeds
- milk, yoghurt, cheese, or calcium-enriched plant alternatives.
Over the four years we spent working on the last revision of the Dietary Guidelines for Australians, it proved impossible to get any consensus on what to call the foods and drinks that don’t fit into the food groups.
Some could definitely be described as ‘junk’ as they contribute little or no nutrients. Others have the potential to make some contribution to nutrient intake but any such virtues are counteracted by their quantity of undesirable types of fat or added sugars or high levels of salt.
Many people use the term ‘junk’ foods. Health officials traditionally called them ‘extras’, but the food industry got their way and the guidelines used ‘discretionary’ choices. As many of us predicted, it turned out that few people had much understanding of how much ‘discretionary’ choices would mess up diet and health.
Whether foods that don’t fit the five food groups are consumed in place of, or in addition to healthy choices matters. These foods now make up 42% of the average Australian’s kilojoule intake, with even higher levels dominating children’s diets. That puts us as fifth highest consumers in the world (the United States gets the gold, silver goes to the United Kingdom).
With 75% of men, 60% of women and 25% of children above a healthy weight, nutritionists and those of us who work in public health believe these products should be called ‘unhealthy’. They are replacing healthy foods, especially vegetables, fruits and wholegrains. Sadly, no Australian government to-date has ever been prepared to upset the all-powerful processed food companies by using the term ‘unhealthy’.
Researchers around the world are now concentrating on ultra-processed foods (UPFs). These are defined as products that contain ingredients that you wouldn’t find in any home kitchen – items such as protein isolates, modified starches, hydrogenated or inter-esterified oils, and additives such as colourants, flavourings, artificial sweeteners, emulsifiers and thickeners, as well as bleaching, bulking, firming, gelling, glazing, foaming and carbonating agents.
Examples of UPFs include soft drinks with sugar or artificial sweeteners; sweet and savoury snacks and biscuits; many breakfast cereals; sauces and instant soups; many desserts; foods for infants and young children; most fast foods and some sports foods. UPFs are palatable, convenient, easy to eat (most require little chewing so they’re consumed quickly), fairly cheap and aggressively marketed.
Some make health claims – for example, foods for young children may claim they have no added sugar when they’re full of sugar that has been extracted from fruit rather than from sugar cane. It’s still just sugar. Many breakfast cereals project a healthy image by emphasising they have added vitamins even when they have high levels of sugar.
Consuming a small amount of UPF may not be a problem – it’s the quantity that makes them unhealthy. Sadly, UPFs have become a habit and, with food companies creating literally thousands of them, they’re now considered ‘normal’.
Over 70 studies have shown that high consumption of UPFs is linked with excess body fat, type 2 diabetes, heart disease, some cancers, inflammatory diseases such as Crohn’s disease, as well as higher levels of depression and anxiety. Children may also have an increased risk of abnormal levels of blood fats.
Current research is looking at whether the problems associated with UPFs come from the high amounts of added sugars and salt, the unhealthy fats, the additives or the processing methods.
Those marketing UPFs point to their greater shelf life, microbiological safety, cheaper price and their popularity with the public. Some concede that the quantity of UPFs consumed could be a problem, contributing too much fat, sugar or salt. Food companies reject the idea that any processing method or additive(s) could be problematic. Indeed, their technologists suggest they could find substitutes for some of the fat, just as they found sweeteners other than sugar. Recent research shows sugar substitutes have not been successful in reducing weight or preventing type 2 diabetes, and the acidity of artificially sweetened soft drinks damages tooth enamel.
One recent study provided some proof that UPFs lead to excess weight. A group of people with stable weight were admitted to a USA National Institutes of Health live-in facility for 28 days. This meant that everything they consumed, and also their energy expenditure, could be measured. All 20 members of this groups stayed for the full four weeks and were given one of two diets for two weeks and then switched to the other diet.
Both diets were matched for calories, protein, fat, carbohydrate, sugars and dietary fibre, but one was high in UPFs while the other featured unprocessed or minimally processed foods. They were provided with three meals each day and told to eat as much or as little as they pleased. Snacks were also available throughout the day. To avoid small changes during the cross-over period, the researchers compared the final week of each diet, finding that energy intake was 500 Calories/day higher during the ultra-processed diet period. The increases occurred at breakfast and lunch, but not dinner. During the high UPF diet period, the subjects gained weight in line with what was expected by their higher caloric intake.
We need more studies like this, but it seems clear that the term ultra-processed food is going to stay, replacing – and extending – terms such as ‘extras’ or ‘discretionary foods’.
Some consider a finer definition may be needed as a few foods currently included in the five food groups also fit the definition of a UPF. Examples include some breakfast cereals, some breads, sweetened coloured yoghurt or milks, soups, sauces and dressings. Some of these foods may be a good source of dietary fibre or some nutrients.
We’ve known for years that the way bread is made is also relevant for many people. Many packaged loaves are made with rapid dough risers. These additives change the structure of the starch in the flour, reducing the time they take to be digested. This creates an adverse effect for those with, or at risk of, type 2 diabetes.
To add to potential problems, a new research paper suggests that UPFs meet the criteria to be labelled as addictive substances. These criteria were established for tobacco products. That remains to be proved but, if it is correct, we could expect the same obfuscation from the food industry as was previously pushed by the tobacco industry.
As we so often say, further research is needed on addictive potential for UPFs. More research is also needed to pinpoint the culprits in these foods, but we definitely have more than enough evidence that we need to reduce our current consumption of these highly processed food products. If you’re in doubt about them, check the ingredient list on the package. If there are any items that you wouldn’t find in a domestic kitchen, look for an alternative.
Dr Rosemary Stanton OAM
