Ultra-Processed Food (or What Happened to Chicken)

This month, I told Michael Milburn I wanted to dig deeper into the concept of “ultra-processed” food, which we’d touched on last month in our discussion of plant-based burgers.

Milburn said that in one way, it was possible to sum up everything about ultra-processed food simply by looking at what’s happened to chicken which, in its modern form, could actually be considered an ultra-processed food.


Chicken, Melbourne Show. (Photo by fir0002 flagstaffotos [at] gmail.com Canon 20D + Tamron 28-75mm f/2.8 GFDL 1.2, via Wikimedia Commons)

Milburn says animal husbandry has successfully bred birds so big “they can hardly stand on their own legs.” As a result, chicken meat today has about 10 times the fat — and 2.5 times the calories — it had 100 years ago. And because it’s often soaked in brine before being put in supermarket display cases, it also has a higher salt content, so it has that addictive salt/fat content that (along with sugar) are hallmarks of ultra-processed food. The salt/fat factor will probably make you eat more than your counterpart from the 1960s would have, but even if you eat the same piece of chicken as people did 150 years ago — or 50 years ago, Milburn says that piece of chicken now has more calories.

So even a chicken is in a sense an ultra-processed food. Especially by the time you turn it into a chicken nugget, it absolutely is.

As it turns out, it’s very difficult to talk about ultra-processed food without talking about a bunch of other things — particularly the link between ultra-processed foods and obesity, which actually became the main theme of our discussion. But I decided to go with it because I found it all interesting. (We also wandered off on a few tangents, which I’ve included as annotations because they were also interesting.)

But first, in case you’ve forgotten (or didn’t read last month’s piece), ultra-processed foods (or “food-like substances” as the writer Michael Pollen has dubbed them) are created in laboratories by breaking actual foods down into their component parts then reassembling some of those parts into a food “product” that generally includes added salt, fat and/or sugar.

The link between ultra-processed food and obesity is complex — we’ll do our best to pick apart a number of the threads — but it all begins, at least, it did for us, with bologna.


The last time we’d spoken, Milburn had said in passing that it wasn’t as if people had eaten particularly well in the ’50s and ’60s, when there was no problem with obesity.  Specifically, what he said was:

I mean, people ate a lot of bologna.

Which got me thinking about other foods that have traditionally been part of the local diet that aren’t exactly health foods, like boiled dinner and anything involving salt cod (no, not anything, fishcakes, which I love).

“Yes,” said Milburn, “and people ate a lot of cakes and pies and huge amounts of sugar.”

And yet, they weren’t generally overweight, a fact which began to change in the 1970s, as these visual aids (which show the rates for the United States) illustrate:

If you ask, “What changed in the ’70s?” one of the answers, says Milburn, is the advent of ultra-processed foods and the evidence linking them to obesity and health problems got stronger this May with the publication —  in Cell Metabolism — of a study that found heavily processed foods caused overeating and weight gain.

Conducted by researchers at the US National Institutes of Health (NIH), the study was small in scale, but it constituted the first “randomized, controlled research of its kind,” meaning it was the first time a study “randomly assigned people to eat specific foods and then measured the results.” According to the NIH, previous studies of large groups of people had shown associations between high consumption of ultra-processed foods (which the NIH defines according to the NOVA food classification system as foods containing “ingredients predominantly found in industrial food manufacturing, such as hydrogenated oils, high-fructose corn syrup, flavoring agents, and emulsifiers”) and health problems, but:

…because none of the past studies randomly assigned people to eat specific foods and then measured the results, scientists could not say for sure whether the processed foods were a problem on their own, or whether people eating them had health problems for other reasons, such as a lack of access to fresh foods.

So, researchers with the NIH’s National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) admitted 20 adult volunteers, 10 male, 10 female, to the NIH Clinical Center for a month and:

…in random order for two weeks on each diet, provided them with meals made up of ultra-processed foods or meals of minimally processed foods. For example, an ultra-processed breakfast might consist of a bagel with cream cheese and turkey bacon, while the unprocessed breakfast was oatmeal with bananas, walnuts, and skim milk.

The ultra-processed and unprocessed meals had the same amounts of calories, sugars, fiber, fat, and carbohydrates, and participants could eat as much or as little as they wanted.

Source: NIH

Source: NIH

Do you want to take a guess as to what happened?

On the ultra-processed diet, people ate about 500 calories more per day than they did on the unprocessed diet. They also ate faster on the ultra-processed diet and gained weight, whereas they lost weight on the unprocessed diet. Participants, on average, gained 0.9 kilograms, or 2 pounds, while they were on the ultra-processed diet and lost an equivalent amount on the unprocessed diet.

Over time, said NIDDK Director Griffin P. Rodgers, MD, those calories add up and the extra weight can “lead to serous health conditions.”

What researchers next need to figure out, said the study’s lead author, Kevin D. Hall, is “what specific aspect of the ultra-processed foods affected people’s eating behavior and led them to gain weight.”

The next step is to design similar studies with a reformulated ultra-processed diet to see if the changes can make the diet effect on calorie intake and body weight disappear.

(It strikes me that the producers of ultra-processed foods, who have calibrated them so carefully to make people crave them, probably know the answer to this question. I guess you can’t just straight up ask them, though.)



Milburn has some theories of his own as to why we eat more ultra-processed foods.

People who’ve studied obesity say there are three basic reasons why people eat too much food: calorie density, eating frequency and portion size, and Milburn thinks ultra-processed foods mess with all three.

Empty 6.5 oz coke bottle.

Empty 6.5 oz coke bottle.

Calorie density just means how many calories are contained within a certain volume of food, and ultra-processed food is “a lot more calorie dense” because it just doesn’t have much fiber.”

If you look at fruits and vegetables and things like whole grains and all those kind of things, like beans, lentils…those kind of foods tend to be very nutrient dense but not very calorie dense, and they have a lot of fiber. Like, anybody will tell you if they go to Louisbourg and have the soldier’s bread, they say, “I can’t eat much of it because it’s too filling.” Exactly the point.

(Full disclosure: My first reaction to the soldier’s bread at Louisbourg was, “I hope I don’t drop this on my foot.”)

As for portion size, Milburn says ultra-processed food is so cheap (thanks to fundamental changes in agriculture) that “food companies can afford to give you very large portions of it….Think about pop sizes, when I was a kid, pop was a little tiny bottle and now they can afford these giant-sized things that cost so little.”

I’m going to say probably it’s in the nature of the ultra-processed food itself that it doesn’t make you full and it kind of raises the blood sugar and then the blood sugar falls and when it falls, you’re basically hungry.

(Although there are cultural effects at work here too, Milburn says, like the tendency to include “snacks” in any organized activity for children.)

The ultra-processed food is so quick and easy to eat, that’s one of the key features of the food — you don’t have to chew it much…there’s not much fiber, it’s all re-assembled so it’s very quick to eat. People can more or less eat very quickly and probably that gets you to overshoot…that mechanism where you feel full takes a little while [to register].


At this point, Milburn reiterated something he’d said in our original discussion, which is that people’s poor food choices are really society’s poor food choices: it’s hard to avoid the food that everyone else is eating. Especially when that food has literally been engineered to make you like it (and eat too much of it):

The challenges people face really have to do with, first of all, taste — you want to be able to eat food you like and if you’re used to liking food that’s basically ultra-processed food with lots of fat/sugar and salt combinations, then you’re dealing with a personal challenge to learn to like real food. And …it’s available, you go to the grocery store, you do have apples, you can buy all sorts of real food, it’s there, but you’re just not used to knowing how to prepare it in ways that make it taste good…

And then the other challenge is the social realities of going to restaurants and eating at other people’s homes…[I]f everybody else is eating that food, it’s hard for you to be different, as it were, from everybody else. It’s a difficult thing for people to do because we’re profoundly social beings.

You go to somebody’s house, it’s pretty rare that somebody’s going to feed you kale with some apples, they’re going to feed you pies, cakes cookies, whatever.

If you can steel yourself against the siren call of salt and sugar and fat, though, Milburn says the health effects can be amazing. But that’s a topic for another day.

I will leave you, once again, with a video from a community video project by friend-of-the-Spectator Madeline Yakimchuk. In today’s episode, Dr. Milburn explains the mystery that is the modern chicken:





Dr. Michael P. Milburn (BSc, MSc, PhD, DipAc, DAc) has a background in science, training in complementary medicine, and two decades of experience with alternative approaches to healthcare. In his clinical work, he finds individualized solutions to common chronic health problems, incorporating Tai Chi, Qi Gon, nutrition, cooking, acupuncture and herbal medicine.