Extreme beliefs often incite extreme actions, so I thought a wild story I was told years ago might just be true.

That the famous doctor who insisted a high-fat diet led to weight loss and promoted heart health and the famous doctor who insisted it led to weight gain and promoted heart disease started duking it out during a debate orchestrated by the U.S. Department of Agriculture.

“The Great Nutrition Debate” did indeed happen, and Robert Atkins and Dean Ornish did indeed attend. You can find it on YouTube.

The fisticuffs, unfortunately for me, did not.

The down and dirty details of a dustup over diet would’ve served as the perfect lead-in for what comes next. That today’s proliferation of ultraprocessed foods and the damage it’s doing to our health - including our children’s - should make you fighting mad.

But don’t go punching out the guy stocking the shelves at your local grocery store or the girl wiping down the tables at the fast-food restaurant. While I’d never advocate violence, the time to forgo UPFs has arrived.

It’s bad enough that the obesity rate for U.S. adults currently hovers around 40 percent, but what’s arguably worse are the current numbers the Centers for Disease Control and Prevention have for 6- to 11-year-olds and 12- to 19-year-olds.

While their obesity rates are much lower, 20.3 percent and 21.2 percent, both are oh-my-god increases of more than 300 percent since the early 1970s.

Which just happens to be the time when a surplus of wheat and corn in the U.S. led to a big increase in the production of UPFs. While it’s improbable UPFs are solely responsible for one out of every five kids weighing an unhealthy amount, it’s safe to say their ubiquity and immediacy plays a large part.

How large? I couldn’t say.

But Fang Fang Zhang, MD, PhD, associate professor, Tufts University School of Nutrition Science and Policy, Boston can say two-thirds of all the calories now consumed by children and teens come from UPFs.

Zhang and colleagues learned this by reviewing 20 years of data accrued from the U.S. National Health and Nutrition Examination surveys. They also learned that UPFs contain only about half the protein, far less fiber, and six times more added sugar than minimally processed foods.

If you’re a bit hazy on the difference between the two, here’s some help.

While minimally processed foods get frozen, canned, smoked, or pasteurized, the changes to UPFs don’t end there. To augment mouthfeel, taste, convenience, and profit, a combination of sugars, fats, artificial flavorings and chemical preservatives are also added.

The addition of any of these makes the food ultraprocessed - and harmful. Not only for children and teens but also adults.

Especially if those adults get 80 percent of their daily calories from UPFs, as one out of every five in the United Kingdom do. Because of that, Chris van Tulleken, a doctor who doles out medical and health advice on the telly for the BBC, changed his diet dramatically for 30 days for a made-for-TV experiment.

To eat as every one in five of his countrymen do, van Tulleken increased his normal ingestion of UPFs by 75 percent.

Throughout the experiment, van Tulleken reported feeling anxious, unhappy, and sluggish, that he had trouble sleeping and defecating, and suffered from heart burn and a low sex drive.

If you’re skeptical of van Tulleken’s claims, bear in mind Rachel Batterham, a professor who heads an esteemed obesity research center in England, oversaw the experiment. She regularly tested van Tulleken and documented physical changes that support his assertion that by the end he felt 10 years older.

Batterham recorded a weight increase in van Tulleken of more than 14 pounds, which changed his body mass index from normal to overweight. Moreover, Batterham, found 30 percent more of the hunger hormone ghrelin in van Tulleken’s blood at the conclusion of the experiment than before, along with a decrease in the fullness hormone leptin.

But what really surprised Batterham were the differences she saw in the before-and-after MRI brain scans. Thirty days of the diet seemingly reworked the area of van Tulleken’s brain that drives repetitive automatic behavior, a reworking that made him desire UPFs morning, noon, and night.

In essence, he was addicted.

Van Tulleken agreed, acknowledging that he had a constant craving for foods like pizza, fries, and chocolates, and said this to Batterham in a snippet of the BBC documentary, “What Are We Feeding Our Kids?” found on YouTube: “Children’s brains are more malleable than mine, which means the changes are likely to be even greater.”

It was a conclusion Batterham had already reached. Because of it, she was limiting the amount of UPFs her children eat even more strictly than before.