https://www.npr.org/2019/05/17/724234175/researchers-say-evidence-shows-what-you-eat-really-does-matter
This study has been making the rounds on various news outlets.
The difference between this study and others is it was under totally controlled environment. Those who participated spent a whole month at the testing facility so the scientists could monitor exactly what foods they ate and in what quanity.
One group got the ultra-processed foods, the other got the as natural foods as possible.
After two weeks, the two groups switched diets.
If I can find the more detailed article, I will post it.
I heard it on the radio.