PostHole
Compose
Login
What Are Ultraprocessed Foods, and Are They Bad for You?
More than half of our diet consists of foods that have been industrially processed in some way, and they may be harmful to our health
Learn more about your ad choices. Visit megaphone.fm/adchoices
November 1, 2023
What Are Ultraprocessed Foods, and Are They Bad for You?
More than half of our diet consists of foods that have been industrially processed in some way, and they may be harmful to our health
By Tanya Lewis, Josh Fischman, Lori Youmshajekian, Carin Leong & Elah Feder
[Illustration of a Bohr atom model spinning around the words Science Quickly with various science and medicine related icons around the text]
Apple | Spotify | YouTube |RSS
Tanya Lewis: Hi, this is Your Health, Quickly, a Scientific American podcast series!
Josh Fischman: We bring you the latest vital health news: discoveries that affect your body and your mind.
Lewis: And we break down the medical research to help you stay healthy.
On supporting science journalism
If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.
I’m Tanya Lewis.
Fischman: I’m Josh Fischman.
Lewis: We’re Scientific American’s senior health editors.
Fischman: On today’s show, we’re talking about ultraprocessed foods—what they are, whether they’re bad for you and why it’s so hard to study their effects.
[Clip: Show theme music]
Lewis: I don’t know about you, Josh, but I’m a big fan of ice cream. I often eat cereal for breakfast, sometimes with a bit of fruit yogurt. And I enjoy a good gin cocktail. What do you think these foods have in common?
Fischman: Wait a minute. You’re actually giving me a pop quiz?
Lewis: Yes, I am.
Fischman: But there are so many different right answers here. All those foods have a lot of sugar in one form or another. They’ve all been linked to poor health. And they all have fruit as an ingredient, even the gin. Which one are you looking for?
Lewis: The answer I was looking for was that they are all ultraprocessed.
Fischman: Oh. Yeah, of course. But what exactly is “ultraprocessed food,” and how does it differ from “processed” food? Is it bad for you?
Lewis: Here to answer some of these questions for us is our editorial intern, Lori Youmshajekian. She’s writing a news story about ultraprocessed foods. Lori, welcome to Your Health, Quickly!
Lori Youmshajekian: Thanks for having me.
Fischman: Hey there, Lori.
Lewis: So, Lori, I’ve heard of processed foods before. I always thought of them as just any kind of packaged or prepared food, like chips or candy. So what makes a food “ultraprocessed,” and how is that different from just “processed” food?
Youmshajekian: So the rule of thumb is that ultraprocessed foods are the things that you can’t make in your own kitchen. And that’s because they’ve gone through some kind of industrial processing where the ingredients have been changed in a way that you just wouldn’t be able to do with domestic equipment, or there are additives to preserve the food, make it crunchier, shinier, all those sorts of things.
They’re typically designed to be ready to eat and really don’t resemble the raw ingredients they’re made from.
Lewis: What are some examples?
Youmshajekian: You might recognize things like chips or sodas. But also granola bars or breakfast cereals or even protein powders. So it’s a really diverse group of food.
Completely unprocessed food is something basically straight from the farm or your garden, like a potato you just pulled from the ground.
Processed food, in comparison, is kind of everything in between. Just washing a food can be a kind of processing—but so can chopping and also things like canning, drying and freezing.
Fischman: So how much of our diet is actually processed or ultraprocessed?
Youmshajekian: By some estimates, almost 60 percent of what we eat in the U.S. is ultraprocessed. For kids, it's even worse—almost 70 percent of their diet is processed.
Lewis: Wow, that’s a lot. But does the amount and type of processing matter?
Youmshajekian: Yes. The differences in the intensity of processing are captured in something called the NOVA scale.
Fischman: Does NOVA stand for something?
Youmshajekian: Nope, it’s actually just a name! “Nova” means “new” in Portuguese. The system was developed in Brazil about a decade ago as a new way to categorize foods.
Historically scientists would look at foods in terms of the nutrients they contain, like protein, fat or carbohydrates.
NOVA sort of came about because scientists recognized that it’s not just nutrients that might affect the quality and health effects of food, but also the amount of processing they undergo.
So NOVA has four categories: there’s unprocessed or minimally processed food—which are things like eggs and vegetables.
Then there are foods you use to prepare meals but don’t necessarily eat on their own—like oil or butter.
Then there are processed foods, which you make using a combination of those categories—homemade bread, for example.
And the final category is ultraprocessed foods, which involve industrial processing and additives.
Fischman: Almost everything we eat undergoes some amount of processing, right?
Youmshajekian: Right, exactly. One example I’ve seen a lot is peanut butter. You could just crush up peanuts and get peanut butter that’s minimally processed. You could add salt, sugar, and oil and get a processed version. Or some of the peanut butter you find at the store could contain preservatives or emulsifiers, and that makes it ultraprocessed.
Lewis: So Lori, do we know if ultraprocessed foods are bad for our health? What does the science say?
Youmshajekian: Some studies have found links between eating ultraprocessed food and obesity, type 2 diabetes, some types of cancer and even mental health issues. But only a few studies have tried to measure whether it’s these diets that are causing the**poor health.
There’s one really important studyfrom a few years ago that made a big splash in the research world because it actually compared the effects of an ultraprocessed diet to a minimally processed one in a controlled setting. Kevin Hall, a scientist at the National Institutes of Health, recruited 20 volunteers and confined them to a hospitallike area in Maryland to study the effects of different diets.
Lewis: Wait, wait, wait. They confined them there?!
Youmshajekian: Yeah! I mean they could talk to one another and to the staff at the facility, but the idea was to prevent people from running off to the cafeteria to get food.
For two weeks, some of them were given only minimally processed foods—so they would start their day with things like greek yogurt and fruit. Others got only ultraprocessed foods, so things like a bagel with cream cheese, turkey bacon and sugary breakfast cereals. And when each group finished those two weeks, they would switch to the other diet.
Participants were given as much food as they wanted. And what’s interesting is that on the ultraprocessed diet, people actually ate about 500 calories more per day and ended up gaining about two pounds.
On the other hand, on the less processed meal plan it was the opposite: people tended to eat less and lost about two pounds as well.
[...]