The Direct Answer
Sugar alcohols are not worse than sugar in every way, but they are not a clean upgrade either. Sugar raises blood glucose and contributes empty calories; sugar alcohols largely bypass blood sugar spikes but can cause significant digestive distress — gas, bloating, and loose stools — especially in doses common in protein bars. Neither is an ideal ingredient if your goal is whole-food nutrition.
What Sugar Alcohols Actually Are
Despite the name, sugar alcohols are neither sugar nor alcohol in the conventional sense. They are a class of carbohydrates — polyols — that occur naturally in small amounts in some fruits and vegetables but are synthesized at industrial scale for use in processed foods. Common ones you'll find on protein bar labels:
- Erythritol — lowest calorie, mostly absorbed in the small intestine
- Maltitol — highest glycemic impact of the group, often called out by label readers
- Sorbitol — ferments heavily in the large intestine
- Xylitol — commonly used in gum, notable toxicity risk for dogs
- Isomalt — frequently used in "diabetic" candy
Food manufacturers reach for these because they read as "low sugar" on a label while still delivering sweetness. That's the entire business reason they exist in processed food.
How They Compare to Sugar, Head to Head
Blood Sugar and Insulin Response
This is where sugar alcohols genuinely have an edge over sucrose. Most sugar alcohols are absorbed slowly or incompletely, producing a lower glycemic response than table sugar. Erythritol has a glycemic index near zero. Maltitol, however, has a glycemic index around 35 — not nothing, and enough to matter for people actively managing blood glucose.
Sugar, by comparison, hits fast. A sucrose spike drives insulin, and repeated spikes over time create the metabolic wear most people are trying to avoid.
Edge: sugar alcohols — with the asterisk that maltitol is a meaningful exception.
Digestive Tolerance
This is where the trade gets ugly. Sugar alcohols that aren't absorbed in the small intestine travel to the large intestine, where gut bacteria ferment them. The byproduct is gas. At higher doses — and many protein bars contain 10–20g of sugar alcohols — this causes bloating, cramping, and diarrhea that is genuinely disruptive.
Erythritol is better tolerated than most because it absorbs earlier, but individual variation is wide. Some people handle 15g of erythritol fine. Others feel it at 5g.
Sugar doesn't do this. It's absorbed cleanly. The harm from sugar is systemic and cumulative — not immediate and gastrointestinal.
Edge: sugar — if digestive comfort is the only metric. Which is the wrong metric, but worth being honest about.
Caloric Density
Sugar delivers 4 calories per gram. Sugar alcohols range from about 0.2 calories per gram (erythritol) to 2.4 calories per gram (maltitol). If caloric load is the concern, most sugar alcohols are meaningfully lower.
Edge: sugar alcohols — clear win here.
What Happens to the Net Carb Math
Protein bar brands subtract sugar alcohols from total carbohydrates to arrive at a "net carb" number. This is a marketing convention, not a regulated nutritional standard. The FDA does not define or validate net carb claims. Maltitol in particular has a real enough glycemic response that subtracting it entirely from the carb count is — let's call it optimistic math.
Label readers know this. If you're buying bars because the net carbs look clean, check which sugar alcohol is doing the heavy lifting.
Why This Question Comes Up Around Protein Bars Specifically
Protein bars are one of the highest-volume delivery vehicles for sugar alcohols in the American diet. A single bar can contain more sugar alcohols than a person would encounter in a full day of eating whole foods. The "low sugar, high protein" positioning is commercially powerful, and sugar alcohols are the ingredient that makes that label story possible.
This creates a situation where consumers think they're making a cleaner choice than a candy bar, when they're actually consuming a concentrated dose of a fermentable carbohydrate that didn't exist in any human diet until the mid-20th century.
That's not a conspiracy. It's just an honest look at what industrial food optimization produces.
What the Alternative Looks Like
If neither sugar nor sugar alcohols are the goal, the question becomes: what actually sweetens a protein bar without those trade-offs?
The short answer is whole-food ingredients in modest amounts — minimal added sweeteners, nothing fermentable in bulk, nothing that requires a chemistry degree to pronounce. It's a harder bar to make and a more expensive one. Most brands don't bother because sugar alcohols are cheap and the label math works in their favor.
At Genesee, we built our bars around [grass-fed bison tallow and whole-food ingredients](/tallow-protein-bar) — no sugar alcohols, no artificial sweeteners, no seed oils. The formulation comes from a straightforward question: what would former athletes eat if they actually read every label? You can see the full ingredient philosophy on our [transparency page](/transparency).
That's not a knock on every other brand. It's just what we found when we went looking for a bar we'd actually want to eat regularly, and came up empty.
So Which Is Worse?
The honest answer: it depends on what harm you're weighing.
- If metabolic and blood sugar impact is the concern: sugar alcohols (except maltitol) are generally preferable to sugar.
- If digestive tolerance is the concern: sugar wins, at the cost of everything else sugar costs you.
- If you're reading net carb claims on a label: be skeptical. The number is a marketing construct, not a regulated fact.
- If you want neither: that's a reasonable position, and it's the one that drove how [Genesee bars were formulated](/our-story).
Neither ingredient is a villain in trace amounts. In the quantities found in most protein bars, both deserve scrutiny — just for different reasons.
If you're tired of choosing between the sugar spike and the bloat, [check out what we're making at Genesee](/products) — bars built for people who read the label before they eat the thing.