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Which sweeteners upset your stomach? The doses, ranked
Of the sweeteners with a measured threshold, maltitol tolerates the largest single dose (about 0.8 g/kg), then erythritol (0.46) and allulose (0.4); lactitol and sorbitol are lowest (0.25 and 0.17). Six sweeteners have no measured single-dose threshold on file and score as unknowns, not as gentle.
Published · Sources checked 20 Oct 2026 · By Assize Index
Summary
- Background.
- Sugar alcohols and rare sugars can cause bloating and diarrhoea, but “may cause discomfort” labels say nothing about dose. We scored osmotic GI discomfort in tiers from the largest symptom-free single dose in human trials.
- What we found.
- Maltitol 0.8 g/kg (−1, secondary source), erythritol 0.46 (−3), allulose 0.4 (−3), xylitol 0.37 (−5), lactitol 0.25 (−7), sorbitol 0.17 (−7, secondary). Tagatose, isomalt, mannitol, yacon syrup, trehalose, and L-arabinose have no single-dose figure and score −7, the 75th percentile of measured rows.
- What it means.
- Erythritol is the best-tolerated common sweetener on a measured threshold; allulose now scores alongside it. A missing threshold never counts as gentle.
What we ranked
Not sweetness, and not blood sugar — stomachs. For each sweetener that can cause osmotic GI discomfort (bloating, gas, diarrhoea), we took the largest single dose that caused no symptoms in a human trial, per kilogram of body weight, for the more sensitive sex. A single dose in water is the most sensitive test design there is, so it is the fairest way to compare. Our Everyday Health list scores it in tiers: at or above 0.6 g/kg costs 1 point, then 3, 5, and 7 below 0.3 g/kg (see Methods, rule v2026-10-20).
Most to least tolerant
| Sweetener | Symptom-free single dose | Points off | Why |
|---|---|---|---|
| Maltitol | 0.8 g/kg | −1 | Highest threshold here — but see the daily-dose note below. |
| Erythritol | 0.46 g/kg | −3 | Mostly absorbed before the colon; EFSA set its daily limit on this effect. |
| Allulose | 0.4 g/kg | −3 | 0.5 g/kg gave 13 of 29 people diarrhoea in the dose-rising trial. |
| Xylitol | 0.37 g/kg | −5 | At 30 g, 4 of 26 men had symptoms; at 40 g, half did. |
| Lactitol | 0.25 g/kg | −7 | Lowest measured single-dose threshold — about 17 g for a 70 kg adult. |
| Sorbitol | 0.17 g/kg | −7 | Lowest figure here, from a secondary source; gum case reports at 18–20 g a day. |
For a 70 kg adult, 0.4 g/kg is about 28 g at once — roughly two heaped tablespoons of powder in a drink. Doses spread over a day run far higher: maltitol’s daily threshold measured 92 g, lactitol’s 74 g split in two4,5. The single-dose figure is a comparison tool, not a serving suggestion.
Reading the table
- Start with erythritol. Most of it is absorbed before it reaches the colon, which is why it behaves better than the other sugar alcohols. EFSA still set its acceptable daily intake at 0.5 g/kg on the laxative effect — the first daily limit set on an immediate effect like diarrhoea1. In a head-to-head drink test it caused fewer watery stools than xylitol at every dose tried6.
- Allulose used to get a free pass. Until this autumn it carried a warning label and no points, because nobody had filed a dose. Han 2018 supplies one — symptom-free at 0.4 g/kg, diarrhoea in 13 of 29 people at 0.53 — so it now scores −3, same as erythritol.
- Maltitol’s −1 needs an asterisk. Its 0.8 g/kg figure comes from a secondary source citing Koizumi 1983, not yet checked against the paper — we say so on its label. Its well-measured daily threshold (92 g) is the highest here4, which points the same way, but the single-dose number itself is provisional.
- Sorbitol and lactitol sit at the bottom on measured thresholds (0.17 and 0.25 g/kg)2,5. Sorbitol’s figure is also secondary; its case reports — months of diarrhoea at 18–20 g a day from chewing gum — are not.
Six we cannot place yet
Six rows have no symptom-free single dose on file: tagatose, isomalt, mannitol, yacon syrup, trehalose, and L-arabinose. They score −7, the 75th percentile of the rows that do have a figure — untested is not treated as clean, the same rule we use for untested trans fat in oils. Tagatose is the most likely to move: at 30 g about a third of unscreened young men had diarrhoea7, but a symptom-free dose has not been pinned down. When a figure is found and checked, that row moves tier and the rule version goes up.
Not medical advice. Tolerance varies by person, dose, and what else you ate.
Table impact
Already live. These tiers have scored Everyday Health since rule v2026-09-30b; since v2026-10-20 every sweetener score counts down from 0, with these points off unchanged. This entry shows the doses behind the points; the unknowns move when a threshold is found and checked.
On our tables
References
- EFSA FAF Panel. Re-evaluation of erythritol (E 968) as a food additive. EFSA Journal 21(12): e8430, 2023. doi.org/10.2903/j.efsa.2023.8430
- Oku T., Nakamura S. Threshold for transitory diarrhea induced by ingestion of xylitol and lactitol in young male and female adults. J Nutr Sci Vitaminol 53(1): 13–20, 2007. www.jstage.jst.go.jp/article/jnsv/53/1/53_1_13/_pdf
- Han Y., et al. Gastrointestinal tolerance of D-allulose in healthy and young adults. A non-randomized controlled trial. Nutrients 10(12): 2010, 2018. www.mdpi.com/2072-6643/10/12/2010
- Ruskoné-Fourmestraux A., et al. A digestive tolerance study of maltitol after occasional and regular consumption in healthy humans. Eur J Clin Nutr 57: 26–30, 2003. doi.org/10.1038/sj.ejcn.1601516
- Patil D.H., et al. Lactitol and sorbitol daily thresholds, split over a day. Br J Nutr 57(2): 195–199, 1987. pubmed.ncbi.nlm.nih.gov/3552029/
- Storey D.M., et al. Gastrointestinal tolerance of erythritol and xylitol ingested in a liquid. Eur J Clin Nutr 61(3): 349–354, 2007. doi.org/10.1038/sj.ejcn.1602532
- Donner T.W., et al. D-tagatose, a novel hexose: acute effects on carbohydrate tolerance in subjects with and without type 2 diabetes. Diabetes Obes Metab 1(5): 285–291, 1999 (with Buemann 2000 screening data via VKM / FSANZ summaries). pubmed.ncbi.nlm.nih.gov/11225640/
- Koizumi N., et al. Studies on transitory laxative effects of sorbitol and maltitol. Chemosphere 12: 45–53, 1983 — figures via a secondary source, not yet checked against the paper. www.prescribingpractice.com/content/calculation-skills/excipient-induced-laxative-thresholds
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Assize Index. Which sweeteners upset your stomach? The doses, ranked. Behind the Table, 2 Nov 2026. assizeindex.com/behind-the-table/which-sweeteners-upset-your-stomach Reuse terms
Data, not medical advice. For decisions about your own health, talk with a clinician.