How bad are ultra-processed foods? Here are 5 things to know

CNN
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When you open a bag of nacho-flavored chips or cheese puffs, you probably know you’re about to indulge in an unhealthy snack.

The dead giveaway? It’s the delicious, spicy, cheesy, neon orange dust that covers every piece and spreads onto your fingers. Same for frozen pizza and chicken nuggets.

But what about a granola bar? A bag of applesauce? String cheese? Flavored yogurt? Surely these foods – snacks that millions of children and adults eat every day – aren’t bad, right?

Well, it turns out that many fall into the category of ultra-processed foods, depending on their exact ingredients. This type of food has been studied a lot recently and the results are not great.

Ultra-processed foods represent a relatively new way of categorizing foods. Proposed in 2009 by researchers at the University of São Paulo in Brazil, the system, called NOVA, is not based on the type of food it is (meat, cereals, vegetables, etc.) but rather on how it is transformed.

NOVA separates foods into four groups, starting with natural and minimally processed foods in the first category to ultra-processed foods, which use industrial formulations and manufacturing techniques, in the fourth.

“My operational definition of ultra-processed (foods) is you can’t make it in your kitchen at home because you don’t have the machines and you don’t have the ingredients,” said Dr. Marion Nestle , food policy expert, to CNN medical correspondent Meg. Tirrell on the Chasing Life podcast recently. Nestlé is the Paulette Goddard Distinguished Professor of Nutrition, Food Studies and Public Health at New York University.

Listen to more of the conversation between Nestlé and Tirrell here.

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Ultra-processed foods contain additives such as flavor enhancers, colors and thickeners – essentially ingredients you wouldn’t usually use in your cooking. This makes them shelf-stable, easy to prepare (just heat and serve), and in many cases, hard to resist. (The food industry opposes the NOVA system, saying there is no scientific consensus on the definition of ultra-processed products.)

Due to a confluence of historical, regulatory and economic factors, Nestlé said, food companies in the 1980s “did a lot of work trying to determine what combinations of flavors, textures and colors would be most appealing to consumers.” people and began producing foods that would be most appealing. make them a lot of money.

She said tens of thousands of new products have since hit store shelves. “Most of them fail, but those who win win big,” Nestlé said.

Before reaching for a can of soda, a bag of chips, or a frozen dinner, why not learn more about what you’re eating? Here are five things to know about ultraprocessed foods:

Eating a lot of ultra-processed foods is not healthy.

“Today, there have been more than 1,500 observational studies – all demonstrating one consistent finding, that consumption of ultra-processed foods is linked to obesity, type 2 diabetes, heart disease, to certain cancers, to poor Covid-19 outcomes, to overall mortality,” Nestlé said. “Any health problem you can think of that is diet-related is specifically linked to ultra-processed foods.”

The most recent study, published Wednesday in the journal The BMJ, analyzed more than 30 years of data and found that eating ultra-processed foods was associated with a 4% higher risk of death regardless of age. be the cause, including a 9% increased risk of neurodegenerative deaths. . Other studies have linked ultra-processed foods to heart disease, type 2 diabetes, cancer, and mental health disorders such as anxiety and depression.

Nestlé stressed that these studies were observational and not designed to prove causation – that ultra-processed foods were causing these poor health outcomes.

“You can do that when you do a controlled clinical trial,” she said. “And guess what? We have one.

This randomized, controlled clinical trial showed that ultra-processed foods actually cause weight gain.

These types of studies are not easy or cheap to undertake, which is why they are not done more often. To carry out this study, Dr. Kevin Hall, principal investigator at the National Institute of Diabetes and Digestive and Kidney Diseases, asked 20 volunteers to spend four weeks at the National Institutes of Health clinical center in Bethesda, Maryland.

For two weeks, they ate a diet made up of 80 percent healthy ultra-processed foods (think yogurt and whole-wheat bread, not chips and soda). For the other two weeks, they followed a diet containing no ultra-processed foods. Diets were tailored to, among other things, calories, sugar, fat, fiber and macronutrients. Participants did not know exactly what the study measured.

“We basically just asked people to, you know, eat as much or as little food as you want,” Hall told Tirrell. “You should not try to change your weight, (you) should not try to gain or lose weight. Simply eat with the same appetite level as you normally would.

Researchers found that when participants ate an ultra-processed diet, they ate about 500 more calories per day than when they ate a minimally processed diet. This difference in calories was quickly reflected on the scale. Participants gained an average of 2 pounds during the two weeks following the ultra-processed diet and lost 2 pounds on the minimally processed diet. And their blood tests showed lower markers of inflammation when they took the latter.

“If you’re not familiar with nutrition research, you have no idea how important this finding is,” said Nestlé, who was not involved in the study. “Five hundred calories is huge.”

Hall said it’s unclear what causes people to consume more calories when they eat an ultra-processed diet. “One of the things we’re really interested in now,” he said, “is understanding what the mechanisms were.”

Ultra-processed foods are everywhere, and most of us consume them without even realizing it, even when we think we’re eating something relatively healthy, like baked chips or a peanut butter and chocolate sandwich. jelly.

Using data from the National Health and Nutrition Examination Survey, researchers found that ultra-processed foods make up more than half of the diets of American adults. For American children, this percentage is even higher, at 67%.

Ultra-processed foods are cheap and convenient

Yes, it’s true: eating truly “clean” costs more.

“To actually create the minimally processed menu, it cost about 40 percent more than the ultra-processed menu,” Hall said. “That doesn’t even take into account the time it takes to prepare the food, right? So all of these factors probably play a huge role in… the foods that we choose to eat in the real world.

Some ultra-processed foods can provide important nutrients, such as whole-wheat bread and yogurt. And others in Hall’s study didn’t increase caloric intake.

“The snacks were neutral in terms of how many calories (participants) ate,” Hall said. “This shows that not all ultra-processed foods necessarily generate this effect.”

Hall’s team is conducting a new study to determine which ultra-processed foods are harmful and which are neutral, or even healthy.

Americans may soon get more help understanding the health effects of ultra-processed foods. The U.S. Department of Agriculture and the U.S. Food and Drug Administration will soon issue new dietary guidelines, updated every five years. Nestlé said the scientific advisory committee guiding this process was asked to examine the link between ultra-processed foods and poor health outcomes.

We hope these five things will help you better understand ultra-processed foods. Listen to the full episode here to find out how much ultra-processed food Hall eats and what he feeds his children.