What do zero sugar gummy bears do? The unexpected digestive effects explained

October 9, 2025 •

4 min read

Internet anecdotes and viral Amazon reviews have famously detailed the notorious digestive consequences of overindulging in certain sugar-free candies, leaving many to wonder, what do zero sugar gummy bears do? The potent, and often surprising, side effects are directly related to the sugar substitutes used, which can wreak havoc on your gastrointestinal system when consumed in excess.

Quick Summary

Zero sugar gummy bears utilize sugar alcohols like maltitol that are poorly absorbed, leading to severe gastrointestinal issues like bloating, gas, and powerful laxative effects, particularly with overconsumption.

Key Points

Sugar Alcohols Cause Digestive Issues: Poorly absorbed sugar alcohols like maltitol are fermented by gut bacteria, causing gas, bloating, cramping, and a laxative effect.
Maltitol is a Notorious Offender: Candies containing maltitol, such as the infamous Haribo sugar-free gummy bears, are known for their potent and sometimes severe laxative effects due to poor absorption.
Erythritol is Better Tolerated: Erythritol is a sugar alcohol that is mostly absorbed in the small intestine, resulting in fewer digestive issues compared to other polyols.
Moderation is Essential: The severity of digestive side effects is highly dependent on the amount consumed, with high doses causing more problems; manufacturers often warn consumers.
Not all 'Sugar-Free' is Created Equal: Always check the ingredient list to see which sugar alcohols are used, as their impact on your digestive system varies greatly depending on the specific type.
Applies to Many Products: The same digestive risks found in zero-sugar gummy bears exist for many other processed foods containing sugar alcohols, such as gum and baked goods.

Unpacking the Sugar-Free Promise

For those watching their sugar intake due to diabetes, weight management, or personal health preferences, zero-sugar gummy bears seem like a guilt-free indulgence. They offer the sweet taste of traditional candy with a significantly lower calorie count and minimal impact on blood sugar levels. However, the key to their sweetness—sugar alcohols—is also the source of their most infamous side effects. These sugar substitutes are not fully digested by the body, leading to a complex chain of events in the gut that can cause significant distress. Understanding this process is essential for anyone considering these treats.

The Science Behind Sugar Alcohols

Sugar alcohols, also known as polyols, are a type of carbohydrate derived from plant products that are used as sweeteners and bulking agents. Common examples include maltitol, sorbitol, and erythritol. Unlike regular sugar, which is quickly absorbed in the small intestine, sugar alcohols are only partially absorbed. The unabsorbed portion continues its journey through the digestive tract to the large intestine.

Once they reach the colon, resident bacteria begin to ferment them. This fermentation process produces gas, leading to symptoms like bloating, cramping, and flatulence. Furthermore, these sugar alcohols create an osmotic effect, drawing water into the intestines. This influx of water and the fermentative activity can trigger a powerful and often uncontrollable laxative effect, resulting in diarrhea.

Different sugar alcohols have varying levels of absorbability and, consequently, different potential for causing digestive issues. This explains why some sugar-free products are more notorious than others for their gastrointestinal consequences.

The Notorious Maltitol vs. the Milder Erythritol

Not all sugar alcohols are created equal when it comes to digestive tolerance. Products containing maltitol, in particular, gained infamy for their severe side effects, even leading to the discontinuation of certain maltitol-heavy candy lines in some markets. Maltitol is less readily absorbed than other polyols, making it more likely to cause significant gastric distress. On the other hand, erythritol is a sugar alcohol that is almost completely absorbed before it reaches the colon, meaning it is much less likely to cause gas and bloating. However, excessive consumption of any sugar alcohol, including erythritol, can overwhelm the body's digestive system and lead to unpleasant symptoms.

Here’s a comparison to illustrate the differences:


Feature	Sugar-Free Gummy Bears (with Maltitol)	Sugar-Free Gummy Bears (with Erythritol)	Regular Gummy Bears
Sweetener	Maltitol, Sorbitol	Erythritol, Stevia	Sugar, Corn Syrup
Calories	Low (approx. 2.1 kcal/g for maltitol)	Very Low (approx. 0.2 kcal/g for erythritol)	High (approx. 4 kcal/g for sugar)
Carbs (per serving)	Present (from sugar alcohols)	Present (from sugar alcohols)	Present (from sugar)
Blood Sugar Impact	Low to moderate glycemic index	Zero glycemic index	High
Digestive Impact	Significant risk of gas, bloating, diarrhea	Lower risk of gas, bloating, diarrhea	Minimal (unless intolerant)
Laxative Effect	Potent with overconsumption	Rare with moderate consumption	No

Mindful Consumption: How to Avoid Disaster

The most important rule for enjoying zero-sugar gummy bears is moderation. Manufacturers of these candies often include a warning about the potential laxative effect on their packaging. Starting with a small portion and observing your body's reaction is the safest approach. If you find yourself sensitive to certain sugar alcohols, it may be worth seeking out brands that use alternatives like erythritol or stevia, or simply limiting your intake of products containing polyols known to cause issues.

To minimize digestive side effects, consider these tips:

Read the label carefully. Identify which sugar alcohols are used. If maltitol is high on the ingredient list, proceed with caution.
Limit your portion size. Do not consume more than a small handful, especially when first trying a new product.
Stay hydrated. Drinking water can help mitigate some of the osmotic effects, though it won't prevent fermentation.
Listen to your body. Everyone's digestive system is different. Pay attention to how you feel and adjust your intake accordingly.

Beyond Gummy Bears

The principles behind zero-sugar gummy bears apply to many other processed foods marketed as sugar-free. Sugar alcohols are prevalent in everything from hard candies and chocolates to chewing gum and baked goods. For individuals with conditions like Irritable Bowel Syndrome (IBS), these products can be especially problematic, as sugar alcohols are classified as FODMAPs and can trigger painful symptoms. Always check the nutrition facts and ingredient list of any sugar-free or low-sugar item.

Conclusion: The Final Chew

Zero-sugar gummy bears can be a tasty alternative for those seeking to reduce their sugar intake, but their pleasant taste hides a potential for significant digestive upset. The key to their effect lies in sugar alcohols, which can cause bloating, gas, and a laxative effect when consumed in excess. By understanding the different types of sugar alcohols and practicing moderation, you can enjoy these treats without the unpleasant surprises that have made them an internet legend. For more information on sugar alcohols and digestive health, consult resources from trusted health authorities like the National Institutes of Health.

Frequently Asked Questions

Zero sugar gummy bears cause stomach pain due to the use of sugar alcohols, like maltitol, which are poorly absorbed by your small intestine. The unabsorbed sweetener travels to your large intestine, where it is fermented by gut bacteria, producing gas that leads to bloating, cramping, and pain.

Not all zero-sugar gummy bears cause diarrhea, but the risk is significant, especially with overconsumption. The laxative effect is caused by sugar alcohols drawing water into the intestines. Candies containing maltitol or sorbitol are more likely to have this effect than those sweetened with erythritol, which is better absorbed.

Sugar alcohols (polyols) are carbohydrate-based sweeteners used in sugar-free products. They are not fully digested, providing fewer calories and a lower impact on blood sugar. In excess, they ferment in the gut and can cause gas, bloating, and diarrhea due to their poor absorption.

The most effective way to prevent digestive issues is to consume sugar-free candy in moderation. It's recommended to start with a small amount to gauge your individual tolerance. Checking the ingredients for specific sugar alcohols and choosing products with better-tolerated ones like erythritol can also help.

Sugar-free gummy bears can be safe for people with diabetes in moderation, as they typically have a lower glycemic impact than regular candy. However, they still contain carbohydrates from sugar alcohols and can affect blood glucose, so it's crucial to monitor intake and blood sugar levels.

The varying severity of side effects depends on the specific sugar alcohol used. Maltitol is particularly notorious because it is less digestible than others, leading to more pronounced gastrointestinal distress and powerful laxative effects with overconsumption.

No, a 'sugar-free' label does not mean the product is calorie-free. Sugar alcohols contain calories, albeit fewer per gram than sugar. Sugar-free candies are still processed and can contain other caloric ingredients, so it's important to check the nutritional information.