Helpful News About UPFs and Proteins
By Kevin Kolodziejski
On a fall group ride in Pennsylvania some time ago, I heard a story about a less-than-attentive cyclist who rode over a black walnut dropped from a tree onto the side of the road. He crashed and snapped his carbon fork in the process.
Talk about one tough nut, not to mention the need to always be keen-eyed while you ride. But that one tough nut is not nearly as tough as another one: the macadamia nut.
Attempt to shell a macadamia nut using a nutcracker designed for almonds, hazelnuts, and walnuts, and there’s a good chance the metal arms will bend or break. In fact, nearly all macadamias are sold already shelled because doing so requires about 300 pounds of pressure per square inch of force, roughly three to four times more force than is needed to crack a walnut.
That’s just nuts.
So too is the following fact: seven in 10 American adults are obese or overweight.
7 in 10 American Adults Are Obese or Overweight
What’s even crazier is that according to the Centers for Disease Control and Prevention the 70-percent rate has held steady for about 15 years. So you could certainly say that in the good old US of A maintaining a healthy weight is in its own right one tough nut to crack. Extend that metaphor, and you could add that what America needs and has been unsuccessfully searching for is something far more efficacious than a standard nutcracker.
It needs something with more leverage.
Now you, my friend, can gain a good bit of dietary leverage — maybe even enough to crack your own overweight/obesity conundrum — by better leveraging protein. In other words, by acting in accordance with the protein leverage hypothesis.
The Protein Leverage Hypothesis
Don’t let the technical language be a turnoff. Simply stated, the protein leverage hypothesis proposes that your body craves a certain amount of protein and that as a way to ensure you get it, you will continue to feel hungry until a sufficient amount of protein is consumed even if you’ve already eaten enough food to maintain your current weight.
A Norwegian study to be published in the September issue of Appetite finds “strong support” for the protein leverage hypothesis “in line with previous studies in the field.” One of those previous studies (though not directly referenced in that paper) is a randomized crossover trial published in the April 2025 issue of Nature Metabolism. It focuses on ultraprocessed foods because one of the characteristics of most UPFs — besides containing the right mix of added sugars and fats to make them hyperpalatable and thereby a cause of unwanted weight gain — is that they tend to possess little protein.
Enter the Chamber and Eat . . . Mostly UPFs
So researchers recruited 21 young adults all determined to be in good health and on two different occasions had them spend 54 hours in a metabolic chamber. That’s a room structured in such a way that a person’s oxygen inhalation and carbon dioxide exhalation can be measured precisely to determine energy expenditure, calorie burn, and nutrient usage. In both instances, the participants were told to eat as much as they want, and all the meals were UPF-heavy, with UPFs accounting for 84 percent of the total calories.
During one of the 54-hour stays, the UPF-heavy meals consisted of 13 percent protein and 46 percent carbohydrate; during the other, they consisted of 30 percent protein and 29 percent carbohydrate. Except for those two differences, the meals were always matched equally for calories, fat, and fiber and were considered by the researchers to be “equally palatable.”
Both times the participants’ calorie intake was greater than the amount they expended, meaning the UPF-heavy meals did exactly what most UPFs are designed to do: Make you overeat. But as Mike Murray notes in an article about the study for Examine, the overeating was 44 percent less on the higher-protein diet when compared to the lower-protein diet, and the difference averaged out to be 196 fewer calories per day. Moreover, the researchers found during the time the participants ate the higher-protein diet, they expended 128 more calories per day.
More Protein Means a Greater Thermic Effect
This additional calorie burn came not through conscious activity or unconscious movement like fidgeting, but because of what’s known as the thermic effect of food: the energy your body uses to digest, absorb, and process the food you eat. While TEF usually accounts for roughly 10 percent of your total daily calorie burn, that percentage is ultimately determined by another: the percentage of the macronutrients consumed during the day.
Ingested fats require up to 3 percent of their calories to be “wasted” for digestion; carbs waste up to 10 percent. But depending on the types of proteins consumed, between 20 and 30 percent are burned in order for your body to use the rest to construct and repair muscles, organs, skin, and hair, serve as a secondary energy source, and a whole lot more.
In short, the thermic effect of food is something you should never forget. But what’s important to remember from this study?
The Important Takeaways From This Study
First and foremost, that virtually all UPFs, even those high in protein, induce you to eat more than you need to; therefore, placing a limit on your consumption of them, or eschewing them entirely, is a healthy move whether or not you need to watch your weight. Nearly as important, however, is that the idea inherent in the adage “not all calories are equal” also applies to UPFs.
That’s something you should never forget, either, especially in light of the following. That when the participants in the aforementioned study were told to eat as much as they want and the “bad stuff” offered to them was higher in protein, they ate 196 fewer calories a day. Because over the course of a year, that equates to 20.5 pounds.
And that’s not peanuts, those hard-to-crack macadamias — or even those black walnuts that can crash cyclists.
Kevin Kolodziejski began his writing career in earnest in 1989. Since then he’s written a weekly health and fitness column and his articles have appeared in magazines such as “MuscleMag,” “Ironman,” “Vegetarian Times,” and “Bicycle Guide.” He has Bachelor and Masters degrees in English from DeSales and Kutztown Universities.
A competitive cyclist for more than 30 years, Kevin won two Pennsylvania State Time Trial championships in his 30’s, the aptly named Pain Mountain Time Trial 4 out of 5 times in his 40s, two more state TT’s in his 50’s, and the season-long Pennsylvania 40+ BAR championship at 43.