Do Calorie-Free Sweeteners Affect Your Blood Sugar? Here's What Dietitians Say

Calorie-free sweeteners have long been popular for satisfying a sweet tooth. You’ll find them in diet sodas, sugar-free candy, syrups, ice cream and more. But although they contain zero calories, they may still have some surprising effects on your blood sugar. 

To find out how calorie-free sweeteners affect your blood sugar levels, we spoke with registered dietitians to explore what calorie-free sweeteners are and how they differ from traditional sugars. We’ll also cover potential health risks and other considerations you should be aware of when consuming calorie-free sweeteners. Read on to learn more.

What Are Calorie-Free Sweeteners?

Calorie-free sweeteners, or nonnutritive sweeteners (NNSs), are food additives that provide sweetness without adding calories to your diet. They’re often used as sugar substitutes in various foods and beverages to help reduce overall calorie intake while delivering a sweet taste.

Common calorie-free sweeteners include aspartame, sucralose and stevia. Studies have found these sweeteners are 200 to 20,000 times sweeter than sucrose (naturally occurring sugar), so only a tiny amount is needed for the same sweetness you get from sugar.

Do Calorie-Free Sweeteners Affect Your Blood Sugar?

Unlike sugar, calorie-free sweeteners pass through your body without being metabolized into glucose. For instance, aspartame and sucralose, two commonly used sweeteners, have been shown to have negligible effects on blood glucose levels in studies. This makes calorie-free sweeteners a good sugar swap for those with diabetes or those wanting to reduce their added sugar intake, according to the American Diabetes Association.

However, these alternative sweeteners may not be totally benign. “Calorie-free sweeteners generally do not raise blood sugar levels because they aren't metabolized the same way as sugar. However, their effects can vary depending on the type of sweetener,” says Trista Best, M.P.H., RD, a registered dietitian with Balance One Supplements. Recent research points to conflicting study data and suggests that while calorie-free sweeteners may not directly impact blood sugar, some of these NNSs might indirectly affect insulin sensitivity or appetite regulation.,

Things to Consider

Artificial sweeteners like aspartame can make some people feel lousy after consuming them. In some instances, these sweeteners have been associated with headaches or digestive issues in sensitive folks. Additionally, consuming too much of certain sweeteners may have potential long-term health consequences, such as poor gut health or even metabolic syndrome. (This data is conflicting and much of it done in animals, and more research is needed.) 

Overall, moderation of calorie-free sweeteners is key. “While moderate intake should have a minimal impact on overall health, high intake levels may lead to gastrointestinal discomfort,” cautions Erin Palinski-Wade, RD, CDCES, a registered dietitian and author of 2-Day Diabetes Diet. What’s more, their impact can be widely different depending on the individual. “For some, they may find that no-calorie sweeteners can increase the desire for more sweets, whereas others may find using these sweeteners limits cravings,” she says. It’s important to step back and consider how consuming calorie-free sweeteners and the foods that contain them impact you personally.

There are other ways you can enjoy sweet foods—even without the added sugar. “If you want to naturally sweeten your food, consider using pureed fruit as a 1-to-1 swap for added sugar in baked goods, such as pureed prunes, unsweetened applesauce or mashed banana,” says Palinski-Wade. Looking for more ideas? Check out our 10 No-Added-Sugar Desserts in Three Steps or Less.

The Bottom Line

Calorie-free sweeteners allow you to enjoy sweetness without added calories. However, their impact on blood sugar can vary depending on the type of sweetener used. While most calorie-free sweeteners have negligible impacts on blood sugar, some may affect insulin sensitivity or pose potential health risks for gut and metabolic health. If you consume artificial sweeteners, be sure to do so in moderation. Speak with your health care provider or a registered dietitian if you have any questions or concerns regarding calorie-free sweeteners and how they fit into a blood-sugar-friendly diet.