Experts engaged in a contentious debate on the usefulness of the NOVA system, which divides foods into different categories based on how much they have been processed, during a session at a virtual conference sponsored by the American Society for Nutrition.
The NOVA system divides foods into “fresh or minimally processed,” such as strawberries or steel-cut oats; “processed culinary ingredients,” such as olive oil; “processed foods,” such as cheeses; and “ultra-processed foods.” UPFs are defined as “industrial formulations made by deconstructing natural food into its chemical constituents, modifying them and recombining them with additives into products liable to displace all other NOVA food groups.”
According to doctors who presented during the meeting, ultra-processed foods are drawing increased attention, because researchers have been examining them in National Institutes of Health-funded studies and journalists have been writing about them.
During the debate session at the meeting, some experts said that, with obesity and poor health skyrocketing, increased awareness and labeling of UPFs can only be a good thing. In contrast others noted at the meeting that the classification system that has come to be used for identifying UPFs — the NOVA Food Classification system — is too mushy, confusing, and, ultimately unhelpful.
Carlos Monteiro, MD, PhD, professor of nutrition and public health at the University of Sao Paolo, was part of the group favoring the NOVA system’s classifying certain foods as UPFs, during the debate. He drew attention to the extent to which the world’s population is getting its calories from UPFs.
Mexico and France get about 30% of calories from these foods. In Canada, it’s 48%. And in the United States, it’s 57%, Monteiro said.
Studies have found that UPFs, many of which are designed to be exceedingly flavorful and intended to replace consumption of unprocessed whole foods, lead to more overall energy intake, more added sugar in the diet, and less fiber and protein intake, he said.
To further support his arguments, Monteiro pointed to studies suggesting that it is not just the resulting change in the nutritional intake that is unhealthy, but the UPF manufacturing process itself. When adjusting for fat, sugar, and sodium intake, for example, health outcomes associated with UPFs remain poor, he explained.
“I’m sorry,” he said in the debate. “If you don’t reduce this, you don’t reduce your obesity, your diabetes prevalence.”
A study presented by Jacqueline Vernarelli, PhD, during a different session at the meeting suggested there may be other downsides to consuming UPFs. This research, which was based on the U.S. National Youth Fitness Survey, found that poorer locomotor skills among children aged 3-5 and poorer cardiovascular fitness among those aged 12-15 were associated with getting more calories from UPFs.
Those with lower cardiovascular fitness consumed 1,234 calories a day from UPFs, and those with higher cardiovascular fitness consumed 1,007 calories a day from UPFs (P = .002), according to the new research.
“It’s notable here that, although these differences are significant, both groups are consuming a pretty high proportion of their diet from ultra-processed foods,” said Vernarelli, associate professor of public health at Sacred Heart University, Fairfield, Conn., during her presentation.
In the debate session, Arne Astrup, MD, PhD, senior project director at the Healthy Weight Center at the Novo Nordisk Foundation, Hellerup, Denmark, presented an opposing view.
He said the definition of UPFs makes it too difficult to categorize many foods, pointing to a study from this year in which about 150 nutrition experts, doctors, and dietitians classified 120 foods. Only three marketed foods and one generic food were classified the same by all the evaluators.
Referring to the study Astrup cited, Monteiro said it was a mere “exercise,” and the experts involved in it had conflicts of interest.
Astrup touted this study’s size and its appearance in the peer-reviewed journal the European Journal of Clinical Nutrition.
Defending his point of view, Astrup said, “The definition and classification is so ambiguous, and the risk of misclassification is so extremely high, I think we really miss the basic requirement of science, namely that we know what we are talking about,” he said.
If you take an unprocessed food, and insert a “little additive…suddenly it’s an ultra-processed food,” he added.
UPF Definition Doesn’t Flag Some Unhealthy Foods
Susan Roberts, PhD, professor of nutrition at Tufts University, Boston, was a discussant at the debate and touched on the merits of both sides. She noted that the UPF definition doesn’t flag some “clearly unhealthy foods,” such as table sugar, but does flag some healthy ones, such as plant-based burgers — to which Monteiro said that the system was not a system meant to divide foods into healthy and unhealthy groups, during the debate session.
The inclusion of both healthy and unhealthy foods in NOVA’s definition of a UPF is a serious problem, Roberts said.
“It’s almost like it’s an emotional classification designed to get at the food industry rather than focusing on health — and I think that’s asking for trouble because it’s just going to be such a mess to tell consumers, ‘Well, this ultra-processed food is healthy and this one isn’t,’ ” she said. What’s happening is the term ultra-processed is being used interchangeably with unhealthy.
The discussion that the UPF classification has generated is useful, Roberts continued. “This definition grew out of that recognition that we’re engaged in an unprecedented experiment of how unhealthy can you make the world without having a major catastrophe.”
She added that the UPF concept deserves a more formalized and rigorous evaluation.
“This is an important topic for the future of public health, and I think it needs big committees to address it seriously,” she said. “I think we should not be dealing with this individually in different labs.”
Doctor’s Take on Usefulness of Discussing UPF Concept With Patients
Mark Corkins, MD, who did not participate in the debate at the meeting, said he talks to parents and children about nutrition at every office visit in which he sees a child with an unhealthy weight.
“Persistence wears down resistance,” said the chair of the American Academy of Pediatrics nutrition committee, in an interview. “A consistent message — you say the same thing and you say it multiple times.”
The idea of “ultra-processed foods” plays a role in those conversations, but largely in the background. It’s a topic that’s important for pediatric health, Corkins said — but he doesn’t make it the focal point.
“It’s not a direct attack on ultra-processed foods that usually I take as my direction,” said Corkins, who is also chief of pediatric gastroenterology at Le Bonheur Children’s Hospital in Memphis, Tenn. “What I try to focus on, and what I think the American Academy of Pediatrics would focus on, is that we need to focus on making the diet better.”
He added, “Parents are aware — they don’t call it ultra-processed food, they call it junk food.”
Corkins continued that he is reluctant to directly challenge parents on feeding their children unhealthy foods — ultra-processed or not — lest he shame them and harm the relationship.
“Guilt as a motivator isn’t really highly successful,” he said, in an interview.
Astrup reported advisory committee or board member involvement with Green Leaf Medical and RNPC, France. Roberts reported advisory committee or board member involvement with Danone, and an ownership interest in Instinct Health Science. Monteiro and Corkins reported no relevant disclosures.
This story originally appeared on MDedge.com, part of the Medscape Professional Network.
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