What Is Tagatose? Meet the Rare Sugar Behind Pastel Protein

You read our ingredients, hit the word tagatose, and squinted. Fair. It sounds like a Pokémon or a moon of Saturn. It’s actually the not-so-secret reason our mug cakes taste like dessert instead of tasting like they’re lecturing you about dessert.

Here’s the whole flirtatious backstory.

So what actually is it?

Tagatose is a rare sugar — a real, naturally occurring sugar (a monosaccharide, if you want to impress someone at a party) that shows up in trace amounts in dairy and some fruits. It’s an isomer of fructose, which is a science-y way of saying it’s almost regular sugar, just built a little differently.

One thing it is not: a sugar alcohol. So it doesn’t do the whole erythritol “cooling” thing on your tongue. It browns, caramelizes, and behaves like sugar because, well, it basically is one — just a rarer, better-behaved cousin.

Why we’re into it

Reader, we are smitten. Here’s what tagatose brings to the table (the dessert table, specifically):

• About 62% fewer calories. The FDA recognizes tagatose at roughly 1.5 calories per gram versus 4 for table sugar. (Note: fewer, not zero — anyone selling you “calorie-free” is fibbing.)
• Very low glycemic impact. Only about 20–25% of it is absorbed in your small intestine, so it causes a much smaller blood-sugar and insulin rise than regular sugar.
• Tastes like the real thing. Roughly 90% as sweet as sugar, with a clean, sugar-like finish. No weird aftertaste to apologize for.
• Tooth-friendly. The cavity-causing bacteria in your mouth can’t ferment it into acid — some research even shows it discourages S. mutans, the little gremlin behind cavities.
• Basically a snack for your gut bugs. The part your body doesn’t absorb gets fermented in your colon and feeds your good bacteria — a prebiotic perk.

It’s also GRAS (the FDA’s “Generally Recognized As Safe” designation), so it’s been thoroughly vetted, not smuggled in.

The honest part (because we’re not that kind of brand)

Tagatose is lovely, but our mug cakes are still dessert, not diet food. Each serving has about 25 g of protein, ~350 calories, and 8 g of added sugar. We swapped a lot of the sugar for tagatose so you get the taste without the full sugar bill — but we’re not going to pretend a brownie is a celery stick. It contains egg, milk, soy, and wheat, too.

One more real-talk note: like most rare sugars, a big single dose of tagatose can be a lot for your stomach. At a normal one-mug-cake serving, you’re well within happy-tummy territory.

Make Dessert Count

So yes — tagatose is the little rare-sugar reason our mug cakes taste like dessert instead of penance. Pastel Protein mug cakes pack about 25 g of protein into a warm dessert that’s ready in two minutes — no baking, no blender, no willpower required.

Take your pick: Brownie Points (rich chocolate brownie) or Cinna-Buns (warm cinnamon roll). Each serving has ~25 g protein and ~350 calories, and yes — it contains egg, milk, soy, and wheat.

👉 Pre-order yours now →

FAQ

Is tagatose a natural sugar or an artificial sweetener? It’s a real, naturally occurring sugar (a “rare sugar”) — not an artificial sweetener and not a sugar alcohol. It just happens to be low-calorie and low-glycemic by nature.

How many calories does tagatose have? About 1.5 calories per gram, versus 4 for regular table sugar — roughly 62% fewer.

Does tagatose spike blood sugar? It has a very low glycemic impact because most of it isn’t absorbed in the small intestine. It’s not a medicine, though — if you manage a blood-sugar condition, talk to your doctor.

Does Pastel Protein taste like it’s sugar-free? No — and that’s the point. Tagatose tastes like sugar, so our mug cakes taste like the dessert you actually wanted.

Sources

• U.S. FDA — supplemental response on D-tagatose labeling (calories 1.5 kcal/g), 2022–2023; FDA GRAS Notice No. 78.
• Critical Reviews in Food Science and Nutrition — tagatose metabolism & glycemic impact, 2021.
• Frontiers in Cellular and Infection Microbiology — tagatose, oral health & prebiotic effect, 2021; Nutrients 16(12):1943, 2024.
• Food Standards Australia New Zealand — D-tagatose human health risk assessment (absorption, tolerance).