High Protein or Junk Protein?

Art created by and is the property of Angela A. Stanton PhD (c)

Context is everything. When it comes to your health, the most important question isn’t just how much protein you’re getting, but what on earth are you eating to get that protein?!

If you eat a donut pumped with a high-protein filling, is it a health food? No. It’s still an UPF.

Art created by and is the property of Angela A. Stanton PhD (c)

Adding protein to junk food doesn’t change its DNA; it’s still junk food—only now it has a better marketing claim. This series is dedicated to unmasking these “junk protein” products so you can make choices based on education rather than labels.

The UPF Catch in this article: Legion Protein Cereal

My first look into UPF in this series was the David Protein Bar, which you can find on my Facebook wall here.

I originally thought it would be a one-off post of some posts that popped up for me advertising it, hence it’s only on FB, but then I was hit with ads for Legion Protein Cereal. After a quick look at the ingredients, I realized this needed to be my first UPF catch on my activist blog. And I also think I should be writing many UPF introductions in a series on junk protein.

Screen capture from Legion Protein Cereal website

Legion Protein Cereal

Legion is another product with a catchy, “clean-looking” name and photos. But don’t fall victim to the branding and high protein claims without understanding what’s in the box! On their website, the ingredient list is buried so deep I could not find it, so I headed to Amazon to find what I needed to see.

At first glance, the “Milk Protein Bites” look simple enough. But when you look at the actual sub-ingredients used to create those bites, the list gets much longer and not so pretty and human-friendly:

• The “Official” List is Simple: milk protein concentrate, soluble tapioca fiber, inulin, coconut oil, powdered sugar, cocoa powder, natural flavors, stevia, and salt. But… did you catch the first item on the list? What exactly is “milk protein concentrate”?
• The Cryptic Item: Within the Milk Protein Concentrate, we find another list, a “sub-list” of sorts. Here is that sub list: Isomalto-oligosaccharide (IMO), pea protein, nonfat yogurt powder, and sunflower lecithin.

I had a bit of difficulty understanding what “pea protein” is doing in “milk protein concentrate”… but I moved on… alas it still bothers me! It’s clearly not milk protein with pea protein in it instead. Is it!! So this is a sort of a lie.. no? OK.. move on to bigger and “better” things: IMO!

IMO: The “Fake” Fiber

The most concerning ingredient in the label is Isomalto-oligosaccharide (IMO). It’s a partially digestible glucose polymer. IMO is a carbohydrate chain made of many glucose units. In plain English: it’s a multi-sugar. It is produced by enzymatically processing starch (usually corn or tapioca) and rearranging the molecules. (Note: “rearranging the molecules” should send shivers up your spine and have the hair stand up on your arms.)

While marketed as a high-fiber ingredient, it is partially digestible in the small intestine (approx. 15–20% digestible), meaning some portion is absorbed as sugar, which leads to a glycemic response. In fact, a study looked into a paradoxical hyperglycemic response to IMO. The glycemic response is considerably higher to IMO than to dextrose—see here—and in a performance study using the IMO vs. dextrose, blood glucose rose less acutely with the IMO bar but insulin:glucose ratio was higher-meaning it spiked insulin more to end with the same blood glucose response (see study here).

IMO is a short-chain carbohydrate made of glucose units. It is literally a multi-sugar, even though it’s often marketed as “fiber” or “prebiotic.”

The name actually means:

• Oligo- = few
• Saccharide = sugar
• Isomalto- = glucose units linked mostly by α-1,6 bonds (the same linkage found in dextrins and parts of starch)

IMO = short chains of glucose molecules, so not fiber in the classic sense. IMO is not a natural whole-food carbohydrate.

It is produced by:

1. Taking starch (usually corn or tapioca)
2. Enzymatically breaking it down
3. Rearranging glucose units into short chains

So it’s enzymatically processed starch. Companies like IMO because it sits in a gray zone:

• Sweet (about 30–60% as sweet as sugar)
• Syrupy and cereal-friendly texture
• Can be labeled as fiber in some countries
• Historically allowed to be under-counted for calories or carbs

What happens to you physiologically as you eat IMO:

Despite the marketing, a significant portion of IMO is digested into glucose in your body. It does raise blood glucose and insulin. While the rise is slower than the rise eating pure glucose, it is stronger than expected. Human studies showed that IMO:

• Has a higher glycemic impact than true fiber
• It is partially absorbed, not inert
• Acts more like a slow carbohydrate than a fiber

So calling it fiber is misleading, even if legally permitted to do so in some places—US being one of those places. Since IMO is shown to be partially digested and fermented, it causes bloating, gas, diarrhea and cramping.

The rest of the ingredients

Soluble tapioca fiber: water-soluble dietary fiber derived from cassava root starch, processed to act as a prebiotic sweetener and texturizer.

Inulin: a natural, soluble prebiotic fiber found in various plants like chicory root, garlic, and bananas. As a non-digestible carbohydrate, it passes to the lower gut

Powdered sugar (sugar + cornstarch): is made by finely grinding granulated sugar and mixing it with a small amount of cornstarch, usually about 3% to 5% by weight. The cornstarch acts as an anti-caking agent, preventing the sugar from clumping and keeping it free-flowing.

Natural flavors: according to the FDA, extracts or essences derived from natural sources—plants (spices, fruits, vegetables, herbs, roots, bark) or animals (meat, dairy, seafood)—used specifically to enhance the taste of food rather than add nutritional value. While sourced from nature, these ingredients are highly processed in laboratories to create specific, concentrated flavor profiles.

Stevia leaf extract: sweet-tasting compounds called steviol glycosides, primarily Rebaudioside A, which are 200-400 times sweeter than sugar. In nature, many glycosides act as antinutrients or plant defenses (toxins) to prevent animals from eating the plant. What are those glycosides?  

When you look up what glycosides are (straight Google quote):

“…glycosides act as antinutrients, specifically within the category of plant-based toxins. Cyanogenic glycosides and glucosinolates interfere with nutrient absorption or cause toxicity by reducing nutrient bioavailability (e.g., binding minerals, affecting iodine uptake). In nature, many glycosides act as antinutrients or plant defenses (toxins) to prevent animals from eating the plant. They are natural defenses found in foods like cassava, beans, and cruciferous vegetables.”

I would not eat a toxic plant product just because it is sweet! I’m wary of consuming these concentrated extracts when better alternatives like allulose, monk fruit exist, and erythritol are available.

Should You Eat Legion Protein Cereal?

Art created by and is the property of Angela A. Stanton PhD (c)

I can’t tell you what you should or shouldn’t eat. It is up to you how much poison you wish to take in for a little pleasure. But I can tell you this: you will not be seeing me eat a single bite.

What products have you seen lately that seem “too good to be true”? Drop a comment with the name and a link, and I’ll put them under the microscope in my next post!

Comments are welcomed as always and are censored for appropriateness.

Angela