Ultraprocessed foods comprise more than half the calories the average American adult eats. They’re also linked to a wide variety of health issues including heart disease, obesity and diabetes. CNN’s Meg Tirrell visits the NIH where researchers are trying to determine why ultraprocessed foods lead to such poor health outcomes and why it’s so hard to stop eating them.
Americans love ultraprocessed foods. Science wants to know why

Ultraprocessed foods comprise more than half the calories the average American adult eats. They’re also linked to a wide variety of health issues including heart disease, obesity and diabetes. CNN’s Meg Tirrell visits the NIH where researchers are trying to determine why ultraprocessed foods lead to such poor health outcomes and why it’s so hard to stop eating them.

3:50 • Source: CNN
Health 9 videos
Ultraprocessed foods comprise more than half the calories the average American adult eats. They’re also linked to a wide variety of health issues including heart disease, obesity and diabetes. CNN’s Meg Tirrell visits the NIH where researchers are trying to determine why ultraprocessed foods lead to such poor health outcomes and why it’s so hard to stop eating them.
Americans love ultraprocessed foods. Science wants to know why
3:50
Now playing
• Source: CNN
Marcello00.png
Inside the viral world of peptides
7:46
Now playing
• Source: CNN
thumb_22844243_942895.193_thumb.jpg
Cyclosporiasis patient describes how illness ruined her honeymoon
1:16
Now playing
• Source: CNN
thumb_22836858_73406.861_thumb.jpg
Public health official on rapidly expanding cyclosporiasis outbreak
1:34
Now playing
• Source: CNN
measles offit still.jpg
Dr. Paul Offit: 'No,' the US cannot still claim to have measles elimination status
1:31
Now playing
• Source: CNN
thumb_22821062_28069.452999999998_thumb.jpg
False positive test creates cyclosporiasis confusion
1:21
Now playing
• Source: CNN
meg.png
Trump’s funding cuts created ‘the perfect storm’ that slowed the government’s cyclosporiasis response
3:40
Now playing
• Source: CNN
Screenshot 2026-07-16 at 2.13.23 PM.png
Canadian wildfire smoke brings dangerous air quality to more than 100 million people in the Midwest and Northeast
2:57
Now playing
• Source: CNN
doctor.jpg
No clear origin as parasitic diarrhea outbreak sickens thousands
2:42
Now playing
• Source: CNN