A higher proportion of ultra-processed food in the diet is generally associated with poorer dietary quality and, among adults, a somewhat higher prevalence of overweight and obesity. This is shown by a study that also critically examines the concept of ultra-processed foods.
The study was conducted at the University of Gothenburg in collaboration with the Swedish Food Agency, using data from the agency’s national dietary surveys. The study population included adults (18–80 years old), adolescents (11–17 years old), and young children (1.5–4 years old).
The objective was to determine what share of the population’s energy intake comes from ultra-processed foods, while also highlighting the challenges associated with how such foods are defined within the internationally established classification system, NOVA.
The NOVA system classifies foods containing additives, as well as certain industrially manufactured products, as ultra-processed, regardless of their nutritional content. Consequently, this category encompasses a wide range of items, from soft drinks and cured meats to breakfast cereals and industrially produced whole-grain bread.
A contested concept
The study’s results show significant variation depending on whether a broad or narrow definition, within the framework of the NOVA classification system, was applied. According to one classification, ultra-processed foods accounted for an average of 45 percent of energy intake among adults, 52 percent among adolescents, and 46 percent among young children.
Under a stricter NOVA-based classification, where foods with ambiguous status were not counted as ultra-processed, the estimates ranged between 23 and 29 percent of total energy intake.
"Ultra-processed foods have received a great deal of attention in recent years, but the concept itself is a subject of debate. There is an ongoing discussion regarding the challenges of classifying foods as ultra-processed and what aspects of a person's diet this classification actually captures," says Linnea Bärebring, a dietitian and associate professor of clinical nutrition at the University of Gothenburg.
What is clear, however, is that adults with a relatively high energy intake from foods classified as ultra-processed had a less nutritionally adequate diet. A high proportion of ultra-processed foods was also associated with a slightly higher BMI in adults, a trend not observed in the younger age groups.
Poorer nutritional content
“We observed that those who derived a larger share of their energy from ultra-processed foods also had a diet containing significantly more added sugar, but less fiber and whole grains. This is a dietary pattern known to be linked to an increased risk of conditions such as cardiovascular disease,” says Torsten Sällström, a dietitian and doctoral student at the University of Gothenburg.
Adolescents with a high energy intake from ultra-processed foods also had a diet with poorer nutritional content. In contrast, for young children, the intake of iron and vitamin E was higher among those with a high consumption of ultra-processed foods. One explanation for this is that iron-fortified ready-to-consume products for children, such as cereal-based gruel and porridge, are classified as ultra-processed.
“It would be unfortunate if parents were to avoid fortified porridge or gruel simply because they are labeled as ultra-processed,” notes Emma Patterson, a nutritionist at the Swedish Food Agency and an associate professor of public health nutrition at Karolinska Institutet.
Limiting the consumption of nutrient-poor, energy-dense foods, such as soft drinks, candy, baked goods, chips, and processed meat products, has long been a dietary recommendation in Sweden. However, the Swedish Food Agency does not specifically advise against everything that might be defined as ultra-processed, as this category can also include nutrient-rich foods.
The study is published in Nutrition Journal.