Lactitol (INS 966): A Comprehensive Guide to This Versatile Sugar Substitute
Answer Snapshot
- What it is: A disaccharide polyol made by hydrogenating lactose, the natural sugar found in milk.
- Safety consensus: JECFA assigned an ADI of "not specified," and FDA and EFSA also accept lactitol in approved food uses.
- Common uses: Sugar-free confectionery, baked goods, dairy products, oral care products, and nutritional supplements.
- Blood sugar impact: It has a very low glycemic effect and does not behave like ordinary sugar in the bloodstream.
- Who should be careful: Large doses may cause digestive symptoms, and people with severe milk allergy should check product labels carefully.
- Label names / aliases: Lactitol, INS 966, E966.
Quick Facts
| Attribute | Detail |
|---|---|
| Ingredient name | Lactitol |
| INS code | 966 |
| Functional class | Sweetener, bulking agent, humectant |
| Sweetness potency | About 30-40% as sweet as sucrose |
| Caloric value | Lower than sucrose; often cited around 1.6-2.4 kcal/g depending on method |
| ADI | Not specified |
| Stability | Typically stable through pH 3.0-8.0 and to about 180°C |
| Blood sugar impact | Very low glycemic response |
| Typical label names | Lactitol, INS 966, E966 |
What It Is
Lactitol is a sugar alcohol derived from lactose by hydrogenation. That process changes the original milk sugar into a polyol with lower available energy and a much smaller blood sugar effect than sucrose.
In formulation terms, lactitol is a bulk sweetener rather than a high-intensity one. It adds sweetness, body, and moisture retention, which is why it appears in foods where simply swapping in a potent sweetener would not recreate sugar's full functional role.
Safety
JECFA assigned lactitol an ADI of "not specified," reflecting a broad safety margin at normal dietary intakes. FDA and EFSA also accept lactitol in approved uses.
The main practical concern is gastrointestinal tolerance. Like other polyols, higher intakes can cause bloating, gas, or diarrhea. Another important nuance is source material: lactitol comes from lactose, so people with severe milk allergy should verify labeling and manufacturer information carefully, even though lactose intolerance and milk allergy are not the same issue.
Metabolism and Blood Sugar
Lactitol is not fully digested in the small intestine and therefore contributes less usable energy than sucrose. A significant portion reaches the colon, where it can be fermented by gut bacteria.
That metabolic pattern leads to a very low glycemic response, which is why lactitol is used in sugar-free and diabetes-conscious foods. It also explains why some formulators discuss its prebiotic potential, although digestive tolerance still depends on total dose.
Stability
Lactitol is stable in many common food systems. It handles acidic to neutral pH conditions and can tolerate processing temperatures up to about 180°C, which makes it practical for baking, confectionery, and dairy applications.
It also functions well as a humectant, helping products retain moisture and texture during storage. That makes it valuable not just for sweetness but for product quality over shelf life.
Common Uses
Lactitol is commonly used in sugar-free candies, chewing gum, chocolate, cookies, pastries, yogurt products, oral care products, and some meal replacements or supplements. It is often blended with high-intensity sweeteners when a product needs more sweetness than lactitol alone can provide.
Its combination of mild taste and bulk functionality makes it especially useful in reduced-sugar foods that still need a sugar-like bite or texture.
Compare and Alternatives
Compared with erythritol, lactitol is usually less cooling and more fermentable in the gut. Compared with isomalt, it offers similar bulk-sweetener functionality but with its own tolerance profile. Compared with stevia or sucralose, lactitol adds body and structure, not just sweetness.
Its main tradeoff is that it is dairy-derived and can cause digestive symptoms at higher doses. Those limits matter most in confectionery and snack products where intake can rise quickly.
Official References
- Codex Alimentarius Lactitol Entry: https://www.fao.org/gsfaonline/additives/details.html?additive_id=966&lang=en (Search: GSFA Online > Additives > Search by INS Code: 966)
- JECFA Monograph on Lactitol: https://www.fao.org/jecfa-monographs/additives/lactitol/en/ (Evaluation of safety and intake levels)
- EFSA Scientific Opinion: https://www.efsa.europa.eu/en/topics/topic/lactitol (Assessment of lactitol’s safety and nutritional impact)
The information provided in this article is for educational and informational purposes only and is not intended as medical advice. People with digestive conditions or severe milk allergy should review product labeling carefully and consult a qualified healthcare professional if needed.