Why do sugar alcohols cause stomach issues?

Most sugar alcohols are incompletely absorbed in the small intestine and ferment in the colon, drawing in water and producing gas. Maltitol is the most notorious because it is used in large quantities; erythritol is mostly absorbed and excreted unchanged, so it is generally better tolerated, though it appears on labels of most “0g sugar” bars.

Is erythritol a sugar alcohol?

Yes. Erythritol is chemically a sugar alcohol (polyol), even though it is better tolerated than maltitol. Bars containing erythritol are excluded from this list; you can see exactly which sweeteners each bar uses on its product page.

Does “0g sugar” mean no sugar alcohols?

No; the opposite is often true. “0g sugar” bars usually achieve that with sugar alcohols or artificial sweeteners. The sugar line on the nutrition panel doesn’t include sugar alcohols, which is why we check the ingredient statement itself.

Protein Bars Without Sugar Alcohols

Sugar alcohols (polyols) like maltitol, erythritol and xylitol keep sugar numbers low, but in larger amounts they are well documented to cause bloating and gastrointestinal discomfort, maltitol especially. We checked the full ingredient statement of every bar in our database; the bars below contain no maltitol, erythritol, xylitol, sorbitol, isomalt, mannitol or lactitol, ranked by protein per 100 calories.

Rankings recompute automatically as new verified products are added. Tap a column to sort; product lines with multiple flavours show their best scoring flavour.

#	Product
1	Built Puff12 flavoursvaries by flavour	17g	140	12.1g	7g	0g
2	Quest BarBlueberry Muffin	20g	180	11.1g	2g	13g
3	Built Sour Puff5 flavours	16g	150	10.7g	8g	0g
4	Atkins Protein BarLemon	13g	150	8.7g	≤1g	8g
5	KIND Protein Max Bar4 flavours	20g	240	8.3g	≤1g	9g
6	Atkins High Protein Bar5 flavoursvaries by flavour	16g	200	8g	≤1g	7g
7	MET-Rx Big 100 Bar2 flavours	32g	410	7.8g	25g	2g
8	Elevation Protein Bar6 flavours	15g	200	7.5g	16g	≤1g
9	IQBAR Protein Bar10 flavours	12g	160	7.5g	≤1g	9g
10	Clif Builders Protein Bar8 flavours	20g	280	7.1g	17g	3g

What counts as a sugar alcohol here

We screen for maltitol, erythritol, xylitol, sorbitol, isomalt, mannitol and lactitol in the verbatim ingredient statement. Glycerin (glycerol) is technically a polyol but behaves differently and is rarely what people mean by “sugar alcohols”, so bars using glycerin are not excluded, and each product page shows the full ingredient list so you can decide for yourself. Bars whose ingredient list we haven’t captured yet are excluded from this page entirely, because an absence claim needs the full label.

How are these bars sweetened instead?

Mostly stevia, monk fruit, allulose, small amounts of real sugar, or artificial sweeteners like sucralose. If you want to avoid artificial sweeteners as well, see the companion ranking of bars without artificial sweeteners.

Popular bars that DO contain sugar alcohols

For comparison, these product lines contain at least one sugar alcohol on their ingredient list (the specific compound is shown). Full details on each product page.

Atkins Filled Soft Baked Protein BarErythritol
Atkins High Protein BarErythritol
Atkins Layered High Protein BarErythritol · 2 flavours checked
Atkins Snack BarErythritol
Atkins Strong High Protein BarErythritol
Atkins Whipped High Protein BarErythritol · 2 flavours checked
Barebells Protein BarMaltitol · 18 flavours checked
David Protein BarMaltitol · 12 flavours checked
Elevation Protein BarMaltitol · 2 flavours checked
FitCrunch Protein BarMaltitol, Sorbitol · 10 flavours checked
Fulfil Vitamin & Protein BarMaltitol · 7 flavours checked
Gatorade Recover Protein BarSorbitol
Grenade Protein BarMaltitol, Xylitol · 4 flavours checked
Kirkland Signature Protein BarErythritol · 4 flavours checked
MET-Rx Big 100 BarMaltitol · 4 flavours checked
No Cow Protein BarErythritol · 9 flavours checked
ONE Protein BarMaltitol · 10 flavours checked
Pure Protein BarMaltitol, Erythritol · 15 flavours checked
Quest BarErythritol · 10 flavours checked
think! High Protein BarMaltitol, Erythritol · 12 flavours checked
think! Layered Protein BarMaltitol

How this ranking works

Every nutrition value is transcribed from the manufacturer’s published nutrition label and verified by hand, with no third party food databases.
Product lines are ranked, not individual flavours, so one product’s 20 flavours can’t fill the list. Each entry shows its best scoring flavour.
A maximum of two lines per brand keeps the list diverse.
Labels that don’t state sugar or fiber are treated as unknown (never as zero) and are excluded from sugar and fiber rankings.
Want to hit a daily protein target? The Protein Pal app lets you scan any label and track your protein day by day.

Frequently asked questions

Why do sugar alcohols cause stomach issues?: Most sugar alcohols are incompletely absorbed in the small intestine and ferment in the colon, drawing in water and producing gas. Maltitol is the most notorious because it is used in large quantities; erythritol is mostly absorbed and excreted unchanged, so it is generally better tolerated, though it appears on labels of most “0g sugar” bars.
Is erythritol a sugar alcohol?: Yes. Erythritol is chemically a sugar alcohol (polyol), even though it is better tolerated than maltitol. Bars containing erythritol are excluded from this list; you can see exactly which sweeteners each bar uses on its product page.
Does “0g sugar” mean no sugar alcohols?: No; the opposite is often true. “0g sugar” bars usually achieve that with sugar alcohols or artificial sweeteners. The sugar line on the nutrition panel doesn’t include sugar alcohols, which is why we check the ingredient statement itself.