Ultra-Processed Foods:

What I Learned from “Ultra-Processed People”

Being the nutrition geek I am, I really enjoy reading books about health and nutrition—even if they have ideas I might not personally agree with. I like to know what’s out there and what other people are reading. Sometimes, I know I can’t recommend these books to clients or other people in my life because they are either too niche or a little dry and overly scientific.

I recently read Ultra-Processed People by Chris van Tulleken, and this book does not fall into that category. It was released in 2023, so the information is very current (as far as nutrition studies go), and it discusses the majority of foods you will find in any grocery store.

If you’ve ever been interested in body composition, energy, inflammation, or long-term health, this book is for you. Written in a style similar to the Super Size Me documentary, the author changes his diet to include only ultra-processed foods. I found this approach refreshing because it gives the book a more realistic perspective than advice coming from a health fanatic who hasn’t consumed any processed foods in decades.

What Is an Ultra-Processed Food?

Van Tulleken uses the NOVA classification system, which groups foods based on how much they’ve been altered from their original form. Ultra-processed foods (UPFs) aren’t just “processed,” like frozen vegetables or canned beans. They are industrial formulations—typically with five or more ingredients—made largely from extracted ingredients, additives, stabilizers, emulsifiers, flavor enhancers, and refined starches.
Examples include:

• Packaged snacks
• Flavored protein bars with long ingredient lists
• Sugary cereals
• Fast food
• Some “health” foods marketed as high-protein or low-fat

The key idea: these foods are engineered for hyper-palatability, shelf life, and profit—not satiety or health.

The Core Argument of the Book

The central claim isn’t simply that UPFs are “bad.” It’s that they are designed in ways that override our natural appetite regulation systems.
Van Tulleken discusses research suggesting that ultra-processed foods:

• Increase total calorie intake (even when matched for macros)
• Are linked to higher obesity rates
• May impact gut health
• Can affect satiety signaling
• Encourage passive overeating

One study he highlighted showed that when people were given diets matched for calories, sugar, fat, and fiber — but one diet was ultra-processed and the other minimally processed — participants eating the ultra-processed diet consumed significantly more calories and gained weight. That’s a powerful point for anyone trying to lose fat but thinking all they need to do is count calories and macros!

It’s Not Just About Willpower

One of the most important themes in the book is this:
Weight gain and overeating may not be primarily about discipline.

Ultra-processed foods are:

• Softer
• Easier to chew
• Faster to eat
• Lower in fiber density
• Designed to hit a “bliss point” of salt, sugar, and fat

That combination makes it easier to consume more calories before fullness kicks in.

For gym members trying to change body composition, this is a big takeaway: Your food environment matters as much as macros. If you are constantly eating on the go and grabbing the quickest option, it doesn’t matter that the package says “30 grams of protein”!

Now, I eat protein bars and drink protein shakes too, but this book made me question how often I rely on them. After reading the book, I thought, I’m going to try to avoid ultra-processed foods for a week. I didn’t even last two days based on my current habits!

The Gut Health Connection

Another theme in the book is how emulsifiers, stabilizers, and additives may alter the gut microbiome. While research is still evolving, some animal and emerging human studies suggest that certain additives may:

• Change gut bacteria composition
• Increase gut permeability
• Influence inflammation markers

This doesn’t mean every additive is toxic. But it suggests our bodies evolved to process whole foods, not industrial formulas. For me, this is a big reason why counting macros only is not always the path to success with clients when they are trying to lose weight or change their body composition.

What This Means for a Gym Community

Here’s the practical takeaway.
You don’t need to fear every packaged food. You don’t need to throw out your protein powder. But you might ask yourself:

• How much of my daily intake comes from whole foods?
• Am I eating foods that naturally regulate appetite?
• Do my meals require chewing?
• Is my plate built around real ingredients?

If this all makes sense, but you’re wondering, “What do I eat instead?”, then contact me for a consultation. I can help you create a plan that fits your goals and your lifestyle.

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About the Author

Liz Foster

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