“Fake sugar” goes by several official names depending on the type. The most common umbrella terms are artificial sweeteners, non-nutritive sweeteners, and high-intensity sweeteners. You’ll also hear “sugar substitutes” and “non-sugar sweeteners,” the term the World Health Organization uses. These all refer to substances that taste sweet but contain few or no calories compared to regular table sugar.
The naming gets confusing because there are actually three distinct categories of sugar replacements, each with its own chemical names, brand names, and properties. Here’s what they all are and how to tell them apart.
High-Intensity Sweeteners
This is the category most people mean when they say “fake sugar.” Six high-intensity sweeteners are approved as food additives in the United States: saccharin, aspartame, acesulfame potassium (often listed as Ace-K), sucralose, neotame, and advantame. They’re called “high-intensity” because tiny amounts produce a sweetness hundreds or even thousands of times stronger than table sugar, which is why products made with them can list zero calories.
You probably know these better by their brand names:
- Saccharin is sold as Sweet’N Low and Necta Sweet.
- Aspartame is sold as Equal and NutraSweet.
- Sucralose is sold as Splenda.
Neotame and advantame are used almost exclusively by food manufacturers, so you’re unlikely to find them in packets on a restaurant table. They all have a glycemic index of zero or close to it, meaning they don’t raise blood sugar the way regular sugar does.
Natural Non-Nutritive Sweeteners
Not all zero-calorie sweeteners are synthetic. Two plant-derived options have become extremely popular in recent years and are generally recognized as safe by the FDA.
Stevia (technically steviol glycosides) comes from the leaves of a South American plant and is 200 to 400 times sweeter than table sugar. You’ll find it sold under brand names like Truvia, PureVia, and Enliten. Monk fruit extract, also called luo han guo, comes from a small melon native to Southeast Asia and is 100 to 250 times sweeter than sugar. Both have a glycemic index near zero.
The WHO groups these natural options together with artificial sweeteners under the single label “non-sugar sweeteners,” which is worth knowing because health recommendations that apply to artificial sweeteners typically apply to stevia and monk fruit as well.
Sugar Alcohols: The In-Between Category
Sugar alcohols are a separate class that often gets lumped in with artificial sweeteners but works differently. Common examples include erythritol, xylitol, sorbitol, maltitol, mannitol, isomalt, and lactitol. Despite the name, they contain no alcohol. They’re called sugar alcohols because of their chemical structure.
Unlike high-intensity sweeteners, sugar alcohols do contain some calories, just fewer per gram than regular sugar. Your small intestine absorbs them slowly and incompletely, which is why they produce a smaller blood sugar spike than regular carbohydrates. This incomplete absorption is also why eating too much of them can cause bloating, gas, or a laxative effect.
The WHO specifically excludes sugar alcohols from its “non-sugar sweetener” category because they do contain calories. On ingredient labels, products must list them separately under “sugar alcohols” on the Nutrition Facts panel.
How to Spot Them on Labels
Food labels don’t always use the names you’d recognize. Aspartame will appear by its chemical name, not as “Equal.” Acesulfame potassium sometimes shows up as “Ace-K.” Sugar alcohols are often listed individually (erythritol, sorbitol, xylitol) rather than under a group name, which can make them hard to identify if you don’t know what you’re looking for. A useful rule: ingredient names ending in “-itol” are almost always sugar alcohols.
Many products combine multiple types. A protein bar might use sucralose for intense sweetness and erythritol for bulk and texture, since high-intensity sweeteners are used in such tiny amounts they can’t replicate the volume that sugar adds to a recipe.
Cooking and Baking Differences
Not all sugar substitutes behave the same way in the kitchen. Aspartame breaks down with heat, so it loses its sweetness during cooking or baking. It works best added after cooking or in cold applications like beverages. Sucralose and saccharin are heat-stable and hold up better in baked goods.
Regardless of which sweetener you use, baked goods made with sugar substitutes won’t brown as much as those made with real sugar. They can also differ in texture and shape because sugar does more than sweeten: it adds bulk, retains moisture, and contributes to the structure of baked goods. Sugar alcohols come closer to replicating these properties than high-intensity sweeteners do, which is why they’re popular in sugar-free cookies, chocolates, and candy.
Safety Limits and Health Considerations
Each approved sweetener has an acceptable daily intake (ADI) set by the FDA, expressed as milligrams per kilogram of body weight per day. Aspartame’s limit is 50 mg/kg, meaning a 150-pound person would need to consume roughly 75 packets of Equal daily to exceed it. Sucralose’s limit is lower at 5 mg/kg, and saccharin’s is 15 mg/kg. These thresholds are set with wide safety margins built in.
In 2023, the WHO released a guideline advising against using non-sugar sweeteners for weight control, concluding that replacing sugar with these sweeteners doesn’t help with long-term weight management. The recommendation applied to all synthetic and natural non-nutritive sweeteners, though not to sugar alcohols. The WHO suggested that people reduce the overall sweetness of their diet rather than simply swapping in calorie-free alternatives. The guideline was classified as conditional, meaning the evidence was suggestive but not definitive.
Erythritol, one of the most widely used sugar alcohols, has drawn particular scrutiny. Research published in American Heart Association journals found that consuming 30 grams of erythritol caused a more than 1,000-fold increase in blood plasma levels and enhanced platelet reactivity in healthy volunteers, a marker associated with clot formation. Earlier studies from the same research group had linked higher fasting levels of erythritol in the blood with increased risk of heart attack, stroke, or death, independent of traditional risk factors. This research is still relatively new, and the clinical significance for people consuming typical amounts remains an open question.