Artificial sweeteners (sugar substitutes) are popular in the United States and other countries. They are consumed by dieters and non-dieters and found in many products. Questions often surface about their impact on health and bodyweight: Is it safe to consume these products? Do they aid in weight loss? Some have suggested that their consumption may be unhealthy. Even though they contain little to no calories it has been suggested that artificial sweeteners may cause weight gain. Those are the two key claims that will be addressed in this article. What does the scientific evidence reveal about artificial sweeteners?
There are a variety of artificial sweeteners on the market (refer to U.S. Food & Drug Administration, 2018, for a listing of artificial sweeteners). Artificial sweeteners are made in the lab and mimic the chemical structure of sugar, so they bind to sweet receptors.* These products are often experienced as being more intense than natural sugars. For this reason, they are sometimes referred to as intense sweeteners. These sweeteners might be hundreds to thousands of times sweeter than table sugar (one new sweetener, advantame, is estimated as 20,000 times sweeter). Two of the most popular artificial sweeteners are sucralose and aspartame.
What Is Sucralose
Sucralose is a zero-calorie artificial sweetener found in the Splenda brand. It is estimated to be 600 times sweeter than sugar. The chemical process involved with producing sucralose involves replacing three hydrogen oxygen groups with chlorine atoms. Splenda contains two calories per teaspoon or one-eighth the calories of sugar (a teaspoon of sugar has sixteen calories). The granular, packet, and tablet forms of Splenda contain a small amount of calories from the bulking agents—maltodextrin, dextrose, and lactose. Sucralose doesn’t have the aftertaste that occurs with some artificial sweeteners.
Baird and colleagues (2000) conducted two studies to investigate sucralose tolerance in healthy humans. In the first study, sucralose was administered at doses of 1, 2.5, 5, and 10 mg/kg of bodyweight at 48-hour intervals, and followed by daily dosing at 2 mg/kg for three days and 5 mg/kg for four days. In the second study, subjects consumed either sucralose or fructose twice daily (participants didn’t know which they were consuming). Sucralose dosage levels were 125 mg/day for weeks 1–3, 250 mg/day during weeks 4–7, and 500 mg/day during weeks 8–12. No adverse experiences or clinically detectable effects were attributable to sucralose in either study. The researchers concluded there is no indication that adverse effects on human health will occur from frequent or long-term exposure to sucralose at the maximum anticipated levels of intake. Some researchers probably won’t consider three months to be “long-term exposure,” so future research should investigate varying durations, including exposure for longer periods.
Research indicates sucralose may be an effective sugar substitute for people with Type 2 diabetes. Grotz and colleagues (2003) investigated the effect of the daily administration of high doses of sucralose, over a three-month period on glycemic control in subjects with type 2 diabetes. The study demonstrated that sucralose consumption for three months at doses of 7.5 mg/kg/day, which is approximately three times the estimated maximum intake, had no effect on glucose levels in individuals with type 2 diabetes. Various studies involving healthy participants who normally consume artificial sweeteners indicate that sucralose has minimal effects on blood glucose and insulin levels. However, a study involving obese participants who did not regularly consume artificial sweeteners reported increases in blood glucose and insulin levels after the consumption of sucralose (Pepino et al. 2013).
Critics of sucralose have suggested it may cause cancer, though after a thorough review, Berry and colleagues (2016) reported “sucralose does not demonstrate carcinogenic activity even when exposure levels are several orders of magnitude greater than the range of anticipated daily ingestion levels.”
Does the consumption of sucralose influence bodyweight? Some studies suggest that sucralose consumption has a positive association with weight gain. Those studies use descriptive and predictive research methodologies; often lack control, and fail to account for various factors that could influence weight gain. In research methodology terms they lack internal validity; cause and effect can’t be determined; numerous factors could influence the outcome. Randomized controlled studies (manipulating levels of sucralose consumption in different groups and randomly assigning participants to conditions) indicate that sucralose often leads to reduced body weight and decreases in waist circumference (Miller and Perez, 2014). In terms of weight loss, it is important to consider overall calorie intake and calorie expenditure. Some people consume sucralose and other artificial sweeteners while consuming excessive calories; in those conditions, weight gain will occur.
There is one important caveat: When using sucralose in high-temperature baking (over 350 degrees), it may break down and lead to the production of harmful substances. More research is needed in this area, so for now it is probably better to avoid using it for baking.
What Is Aspartame
Aspartame is an artificial sweetener consisting of the naturally occurring amino acids phenylalanine and aspartic acid. The sweetener is marketed under the brand names Equal and NutraSweet. It is found in a wide range of products, including diet beverages, supplements, tabletop sweeteners, teas, and deserts. When processed by the body it yields its constituent amino acids, phenylalanine and aspartic acid, and free methanol. Aspartame is 200 times sweeter than sugar.
Critics of aspartame claim that free methanol and phenylalanine present health risks. They may be surprised to find out that the phenylalanine and methanol released from aspartame is small compared to the amount of these substances found in some dietary sources. An aspartame sweetened drink contains 20 milligrams (mgs) of methanol, an equivalent serving of fruit juice produces 40 mgs, and an alcoholic beverage contains 60–100 mgs (Hale 2014). A diet soda contains 100 mgs of phenylalanine compared with 300 mgs for an egg, 500 mgs for a glass of milk, and 900 mgs for a large hamburger. Large quantities of methanol can produce toxic effects, but it is rare for those levels of methanol to be produced when consuming aspartame (Healthline Editorial Team 2018).
Should individuals with phenylketonuria (PKU) ingest aspartame? People with PKU have excessive phenylalanine in their blood; they have a problem metabolizing it. The essential amino acid is found in various protein sources (examples include meat, fish, eggs, and dairy). Numerous health organizations (Food and Drug Administration, the Joint Expert Committee on Food Additives of the FAO/WHO, and the American Medical Association) advise those with PKU to avoid aspartame. As for others, “More than 100 toxicological and clinical studies reviewed confirm that aspartame is safe for the general population” (Henkel 2004).
Does the consumption of aspartame influence bodyweight? There is a lack of evidence showing that the consumption of aspartame causes weight gain; although there are epidemiological studies showing an association between aspartame and weight gain. A review published by De La Hunty and colleagues (2006) examined the evidence for the effect of aspartame on weight loss and energy intakes in adults. Studies that examined the effect of substituting sugar with either aspartame alone or aspartame in combination with other intense sweeteners on calorie intake or bodyweight were identified. Studies that were not randomized controlled trials in healthy adults, and which did not measure energy intakes for at least 24 hours (for those with calorie intakes as an outcome measure) were excluded from the analysis. A significant reduction in energy intakes and increase in weight loss was seen with aspartame compared with all types of conditions, except when aspartame was compared with control groups, consuming only water. The researchers concluded that using substances sweetened with aspartame, instead of those sweetened with sucrose is an effective way to maintain and lose weight without reducing the flavor of the diet.
- Consuming moderate amounts of sucralose and aspartame is probably fine for the majority of health people.
- Avoid using sucralose when baking at high temperatures.
- Avoid aspartame if you suffer from PKU.
- Sucralose and aspartame may aid in weight maintenance and weight loss.
- Consuming excessive calories (with or without the consumption of artificial sweeteners) will produce weight gain.
- Sucralose can often be used by Type 2 diabetics as a sugar substitute.
Baird, I., et al. 2000. Repeated dose study of sucralose in human subjects. Food Chemical Toxicology, 38(2), 123–129.
Berry, C., et al. 2016. Sucralose Non-Carcinogenicity: A Review of the Scientific and Regulatory Rationale. Nutrition and Cancer 68(8). doi https://www.tandfonline.com/doi/full/10.1080/01635581.2016.1224366.
De La Hunty, A., et al. 2006. A review of the effectiveness of aspartame in helping with weight control. Nutrition Bulletin 31(2), 115–128. doi https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1467-3010.2006.00564.x.
Grotz, V., et al. 2003. Lack of effect of sucralose on glucose homeostasis in subjects with type 2 diabetes. Journal of the Amercian Dietetic Association 103(12), 1607–1612.
Hale, J. 2014. Interrogating Nutrition Claims. Seminar Presentation.
Henkel, J. 2004. Sugar Substitutes: Americans Opt for Sweeteners and Lite. U.S. Food & Drug Administration. Online http://web.archive.org/web/20071214170430/www.fda.gov/fdac/features/1999/699_sugar.html.
Healthline Editorial Team. 2018. The Truth About Aspartame Side Effects. Online https://www.healthline.com/health/aspartame-side-effects.
Miller, P., and Perez, V. 2014. Low-calorie sweeteners and body weight and composition: a meta-analysis of randomized controlled trials and prospective cohort studies. American Journal of Clinical Nutrition 100(3), 756–777.
Pepino, M., et al. 2013. Sucralose affects glycemic and hormonal responses to an oral glucose load. Diabetes Care 36(9), 2530–2535.
U.S. Food & Drug Administration. 2018. Additional Information about High-Intensity Sweeteners Permitted for Use in Food in the United States. Online https://www.fda.gov/food/food-additives-petitions/additional-information-about-high-intensity-sweeteners-permitted-use-food-united-states
* Taste receptors are located on the tongue and the roof of the mouth. There are five basic tastes: sweet, salty, sour, bitter, and umami