Sucralose vs. Aspartame: Differences Explained

Learn about sucralose and aspartame, looking at what they are, their benefits, and any risks of consuming either with certain health conditions.

Sarah Bullard, MS, RD, LD
— Signos
Dietitian and Nutrition Writer
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Updated by

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Science-based and reviewed

July 18, 2024
December 18, 2023
— Updated:

Table of Contents

Sucralose and aspartame are popular sweeteners. In fact, in America, about 31% of American adults consume artificial sweeteners from beverages, 10% from foods, and 14% add them to products using the packets.1

These sweeteners are used instead of calorie-containing sweeteners like table sugar, honey, agave syrup, or brown sugar. Due to their low or no-calorie content, they are called non-nutritive sweeteners (NNS), low-calorie sweeteners, artificial sweeteners, or sugar substitutes. Sucralose and aspartame produce an intense sweet taste in a small amount compared to calorie-containing sugars. 

In this article, we will compare sucralose and aspartame, dive into what each sweetener is, and discuss any benefits and risks of consuming them with certain health conditions.


What Is Aspartame?

Aspartame was first approved by the Food and Drug Administration (FDA) in 1974. The FDA considers aspartame to be a food additive. Brand names include Nutrasweet, Equal, and Sugar Twin.2 

Aspartame contains some calories, so it is a low-calorie sweetener. However, aspartame is 200 times sweeter than table sugar, allowing for significantly less to be used for comparable sweetness.2 

Aspartame is made from two compounds: phenylalanine and aspartic acid. These compounds are amino acids found normally in protein-containing foods. When combined, they make aspartame, which is super sweet!2

One packet (1 gram) of Equal contains 3.65 calories and 0.9 grams of carbohydrates.A small amount of aspartame is combined with dextrose or maltodextrin to dilute the sweetness and allow for measuring in recipes.4 

Aspartame is not heat-stable and should not be used in baked goods. When heated, aspartame loses its sweetness. However, sucralose and table sugar maintain their sweetness in cooking and baking.2

Benefits of Aspartame

Aspartame is one of the most studied sugar sweeteners due to the length of time it has been approved by the FDA. The FDA reviewed over 100 studies and continues to review new research.2 

Several studies indicate that aspartame does not affect blood sugar levels, appetite, or body weight, but these are all relatively small studies.1, 5, 6

In 2019, 154 overweight or obese adults were assigned to consume 1.25 to 1.75 liters daily of beverages sweetened with sucrose (sugar), aspartame, saccharin, sucralose, or rebaudioside A (Stevia) for 12 weeks.1 Sucrose and saccharin intake led to an average body weight increase of four pounds. Aspartame and stevia resulted in no weight change, whereas the sucralose group lost three pounds.1

A study from 2012 included 47 overweight adults randomized to either 1 liter of regular sucrose soda, 2% milk, aspartame-sweetened diet soda, or water for six months.5 

Liver, muscle, and abdominal fat increased in the regular soda, with no changes found among the other drinks. Milk and diet soda reduced systolic blood pressure by 10 to 15% compared to regular soda.5

In 2018, The Journal of Nutrition studied 100 healthy body-weight adults and gave them 0, 350, or 1050 mg of aspartame daily for 12 weeks.6 For reference, a 12-ounce can of diet soda contains about 200 mg of aspartame. Neither dosage of aspartame resulted in differences in appetite, body weight, and blood sugar control.6 

What Is Sucralose?

Sucrolose was approved for use by the FDA in 1998. The brand name for sucralose is Splenda. Sucralose is also considered a food additive by the FDA.2,7 

Sucralose is a zero-calorie sweetener and is 600 times sweeter than table sugar. It is made by replacing some of the molecules in table sugar. The structure change prevents sucralose digestion, making it a zero-calorie sweetener or NNS.7

However, one packet (1 gram) of Splenda contains 3.36 calories and 0.9 grams of carbohydrates. A small amount of sucralose is combined with dextrose and maltodextrin, giving it calories.8 

If you check the Splenda website, the granulated Splenda bags contain no calories or carbohydrates as fewer fillers are used.9  

Sucralose is heat-stable, meaning it does not lose its sweetness when heated.2 However, some studies indicate sucralose breaks down at temperatures above 246° Fahrenheit. At 482° Fahrenheit, sucralose can break down into toxic compounds in the presence of stainless steel or metal with rust.10 Adding sucralose to hot or cold beverages would not reach this temperature, but certain baking recipes might.

Benefits of Sucralose

The FDA reviewed over 110 studies related to sucralose.2 Most of these studies are less than 13 weeks and with under 200 subjects.7 Sucralose does not appear to negatively affect blood sugar levels or cause weight gain.7 

As mentioned above, 28 individuals were randomized to drink 1.25 to 1.75 liters of sucralose and lost three pounds after 12 weeks. Other low-calorie sweeteners either did not affect weight or resulted in a four-pound weight gain (saccharin and table sugar).1

In 2019, 34 healthy men were randomized to 780 mg of sucralose capsules daily for seven days. After seven days, there were no changes in blood glucose control, insulin resistance, or gut bacteria in healthy males.11

In a larger study,128 adults living with type 2 diabetes were randomized to receive placebo (cellulose) capsules or 667 mg of sucralose daily for 13 weeks. Sucralose at this dose is about three times the estimated maximum intake. This sucralose amount did not change glucose levels.12

In another study, 47 men without type 2 diabetes consumed 333.3 mg of sucralose or a placebo three times daily at mealtimes. Throughout the study, glucose and insulin markers were within normal limits.13 Research tends to support the idea that sucralose does not impact blood glucose levels. 

Lastly, sucralose, stevia, and saccharine do not cause tooth decay like table sugar. These three sweeteners may have some antibacterial properties preventing bacteria growth in the mouth. Researchers found this after using animal teeth models and applying bacteria and different sweeteners.14 

<p class="pro-tip"><strong>Also Read: </strong><a href="/blog/healthy-sweet-snacks">Snack Smart: 15 Healthy & Blood Sugar-Friendly Sweet Snacks</a>.</p>

The Difference Between Aspartame and Sucralose Explained


Here is a quick summary of the main differences between aspartame and sucralose. 

  • Production

Both aspartame and sucralose are artificial or created in a laboratory, altering the chemical state or joining compounds that are generally not combined.

Aspartame is formed from two amino acids, phenylalanine, and aspartic acid, and tastes very sweet.

Sucralose is derived from altering the table sugar molecule slightly, causing the body to be unable to digest the new compound, resulting in a zero-calorie sweetener. 

  • Taste

Sucralose is 600 times sweeter than sugar, whereas aspartame is 200 times sweeter. You need less sucralose to achieve the desired sweetness. 

Taste-testing 15 different sweeteners and table sugar revealed that aspartame and sucralose were best tasting. Participants perceived aspartame and sucralose to have some bitter, metallic, and chemical aftertaste but overall retained their sweetness profile better than the other sweeteners.15 

Taste is unique. Some people may prefer a particular sweetener over others.

  • Health Impact

The health impact of sweeteners is inconclusive due to mixed findings, differing results from animal studies, or small studies on humans with a short research period. 

The American Heart Association and American Diabetes Association recommend using low or no-calorie sweetened beverages as a temporary substitute for sugar-sweetened beverages.16 Excess sugar intake can make it difficult to control blood glucose levels. This is especially true for adults trying to cut back on their high intake of sugary, sweetened beverages. 

Animal studies have shown that both aspartame and sucralose sweeteners can alter gut bacteria in mice.17 Only small studies have been done on humans over a couple of weeks of intake, with no change noted in gut bacteria.18  

Aspartame is linked to headaches, migraines, or mood changes. Researchers think that aspartame can enhance already present stress levels in the brain for some people.19

  • Effects on Blood Sugar and Metabolism

Both aspartame and sucralose seem to have no impact on blood sugar levels, but keep in mind these are small studies and measure changes in the short term (12 weeks or less). 

Compared to table sugar, many sweeteners result in weight maintenance or weight loss of small amounts over 12 weeks. Individuals lost three pounds for sucralose, no weight change for aspartame, and a four-pound weight gain for those consuming sugar.1 

  • Nutrition

Sucralose is a zero-calorie sweetener, whereas aspartame is a low-calorie sweetener. 

However, in packet form with the addition of fillers (dextrose and maltodextrin), they are comparable at 3.3 or 3.6 calories per gram (1 packet). Sucralose is calorie-free when scooped out of granulated bags containing fewer fillers. 

Which Is Better: Sucralose or Aspartame?

Several factors can help you determine whether sucralose or aspartame is better. Both are comparable in blood glucose control and weight maintenance from available research. That being said, you should be mindful of the amount of sucralose or aspartame you consume daily. The FDA developed Acceptable Daily Intakes (ADI) for six artificial sweeteners approved to be used as food additives and is the amount considered safe to consume daily. The ADI for aspartame is 75 packets, and 23 packets for sucralose.2

When baking, you should avoid aspartame as it loses its sweetness at high temperatures. However, some research shows that sucralose may break down into unhealthy compounds at higher baking temperatures. 

Keep in mind that some research links aspartame to headaches, migraines, or mood changes. It is thought that aspartame enhances present stress levels in the brain for some people. Individuals on medications for pre-existing neurological behaviors should speak with their provider before consuming aspartame.19

Individuals with a rare genetic disorder called phenylketonuria (PKU) need to avoid aspartame as their body cannot digest it, which can lead to brain damage.1 People with kidney disease should avoid long-term consumption of aspartame as it is associated with kidney injury in animals.19 

Consider trying both and see how they taste to you. Sucralose or aspartame may help you transition from a high-sugar to a lower-sugar diet. 

Most health organizations recommend sugar sweeteners to help reduce high added sugar intake temporarily. 

Eventually, limiting all forms of sweeteners is the end goal. The long-term effects of sweeteners are unclear. 

The long-term effects of high intake of sugar and sugar-sweetened beverages are clear: it is detrimental to health. 

Sugar-sweetened beverages (sucrose or table sugar) have been associated with obesity, heart disease, and metabolic syndrome. Metabolic syndrome is a grouping of abnormal lab values and physical markers that often lead to the development of heart disease and type 2 diabetes.5 

Learn More About Healthy Nutrition with Signos’ Expert Advice

A Signos continuous glucose monitor (CGM) can help you track blood glucose levels discretely and conveniently.

This tool (CGM) can help you understand how your body reacts to different foods, beverages, sugar, and sweeteners to help you make effective changes.  

A Signos’ CGM can help you improve your health while trying to prevent or manage type 2 diabetes. 

Learn more about nutrition and healthy habits on Signos’ blog. Take a quick quiz to determine if Signos fits your needs.

<p class="pro-tip"><strong>Learn More: </strong><a href="what-is-sucrose">Sucrose 101: Sucrose And Blood Sugar</a>.</p>

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Topics discussed in this article:


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  2. U.S. Food and Drug Administration. (2023, July 14). Aspartame and other sweeteners in food.
  3. U.S. Department of Agriculture. (2022, October 28). Sugar substitute, aspartame, powder.
  4. Equal. (n.d.). FAQs.
  5. Maersk, M., Belza, A., Stødkilde-Jørgensen, H., Ringgaard, S., Chabanova, E., Thomsen, H., Pedersen, S. B., Astrup, A., & Richelsen, B. (2012). Sucrose-sweetened beverages increase fat storage in the liver, muscle, and visceral fat depot: a 6-mo randomized intervention study. The American journal of clinical nutrition, 95(2), 283–289.
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  12. Grotz, V. L., Henry, R. R., McGill, J. B., Prince, M. J., Shamoon, H., Trout, J. R., & Pi-Sunyer, F. X. (2003). Lack of effect of sucralose on glucose homeostasis in subjects with type 2 diabetes. Journal of the American Dietetic Association, 103(12), 1607–1612.
  13. Grotz, V. L., Pi-Sunyer, X., Porte, D., Jr, Roberts, A., & Richard Trout, J. (2017). A 12-week randomized clinical trial investigating the potential for sucralose to affect glucose homeostasis. Regulatory toxicology and pharmacology : RTP, 88, 22–33.
  14. Giacaman, R. A., Campos, P., Muñoz-Sandoval, C., & Castro, R. J. (2013). Cariogenic potential of commercial sweeteners in an experimental biofilm caries model on enamel. Archives of oral biology, 58(9), 1116–1122.
  15. Tan, V. W. K., Wee, M. S. M., Tomic, O., & Forde, C. G. (2019). Temporal sweetness and side tastes profiles of 16 sweeteners using temporal check-all-that-apply (TCATA). Food research international (Ottawa, Ont.), 121, 39–47.
  16. Johnson, R. K., Lichtenstein, A. H., Anderson, C. A. M., Carson, J. A., Després, J. P., Hu, F. B., Kris-Etherton, P. M., Otten, J. J., Towfighi, A., Wylie-Rosett, J., & American Heart Association Nutrition Committee of the Council on Lifestyle and Cardiometabolic Health; Council on Cardiovascular and Stroke Nursing; Council on Clinical Cardiology; Council on Quality of Care and Outcomes Research; and Stroke Council (2018). Low-Calorie Sweetened Beverages and Cardiometabolic Health: A Science Advisory From the American Heart Association. Circulation, 138(9), e126–e140.
  17. Ruiz-Ojeda, F. J., Plaza-Díaz, J., Sáez-Lara, M. J., & Gil, A. (2019). Effects of Sweeteners on the Gut Microbiota: A Review of Experimental Studies and Clinical Trials. Advances in nutrition (Bethesda, Md.), 10(suppl_1), S31–S48.
  18. Ahmad, S. Y., Friel, J., & Mackay, D. (2020). The Effects of Non-Nutritive Artificial Sweeteners, Aspartame and Sucralose, on the Gut Microbiome in Healthy Adults: Secondary Outcomes of a Randomized Double-Blinded Crossover Clinical Trial. Nutrients, 12(11), 3408.
  19. Choudhary, A. K., & Lee, Y. Y. (2018). Neurophysiological symptoms and aspartame: What is the connection?. Nutritional neuroscience, 21(5), 306–316.
  20. Ardalan, M. R., Tabibi, H., Ebrahimzadeh Attari, V., & Malek Mahdavi, A. (2017). Nephrotoxic Effect of Aspartame as an Artificial Sweetener: a Brief Review. Iranian journal of kidney diseases, 11(5), 339–343.

About the author

Sarah Bullard is a registered dietitian and nutrition writer with a master’s degree in nutrition. She has a background in research and clinical nutrition, personalized nutrition counseling, and nutrition education.

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