Artificial Sweeteners: Are They Safe?

Sweeteners: Are they safe?
By: Miguel Blacutt


Whoever said that you can’t have your cake and eat it too definitely did not know about non-nutritive sweeteners. Non-nutritive sweeteners are natural and artificial sweeteners that contain no calories, or at least very few. For the purpose of this article, the term “sweetener” refers to non-nutritive sweeteners, whether artificial or natural. In this article, I will be going over the most common sweeteners and the research on their safety. Before you read this article, I would like to clear your mind of what you may have read on a popular-media outlet that has no scientific basis. I encourage you to go into this article without any bias. I will be presenting evidence and scientific research that deeply investigates sweeteners and their safety. The science presented in this article is high quality, peer-reviewed research… not your local magazine that is telling you, “Science says: eating chocolate is better than going to the gym!”. Without further ado, let’s get into this and talk about some sweeteners!

Why use sweeteners?

An important question to answer is why we would use sweeteners in the first place. If they had no benefit, then it wouldn’t be worth talking about them to begin with. The benefit of sweeteners is simple yet powerful: they allow you to consume sweet foods and drinks without consuming the large number of calories that usually comes with these items. This benefit means that you can have a diet soda, sweetened yogurt, syrup, chocolate sauce, protein frosties, cookie nookies, all while still progressing towards your fitness goals! As I said, it is a simple benefit but a powerful one. Using sweeteners means that you do not have to ignore your sweet-tooth, you can satisfy it and still be completely on track! Even better, you will have more calories left over to spend on other foods that you like.

Sweeteners and Weight-loss

A study by Pieters et al. looked at a 12-week weight-loss diet in 303 people who were split up in two groups: one group consumed at least 24oz (710mL) of a non-nutritive sweetened beverage per day and one who drank at least 24oz of water per day [1]. At the end of the 12 weeks, the group who consumed the sweetened beverage lost 13lbs while the water group lost 9lbs; a 4-pound difference in only 12 weeks! Further, the group that consumed the sweetened beverage had a greater reduction in total and LDL cholesterol.

Why might this be? Well, sweeteners can do two things for you: help you adhere to your diet and decrease the number of calories that you spend on sweet treats. If you’re craving something sweet, you can satisfy the craving by drinking a zero-calorie Diet Coke instead of consuming 140 calories by drinking a 12oz Coke. Thus, you can satisfy your cravings and adhere to your diet without consuming extra calories doing so.


About the Rat Model

Many of the studies I am about to reference have been done on rats. It is important that you understand that the rat model is the most commonly used in biomedical research for a reason; rats have similar metabolism, cognition, neurology and responses to toxicology to humans. Further, providing a rat with aspartame for 10 weeks is much more significant than providing a human with aspartame for 10 weeks; it has a much larger effect since 10 weeks is a far more significant part of a rat’s life than a human’s. These studies have a lot of applications in humans and must be considered, even though they were not done on humans. If someone questions you for looking at rat data, ask them why they don’t and they will not have a good answer beyond, “Because they’re rats”. However, as I previously said, the rat model is the most common model used in biomedical research for good reason

The Sweeteners

There are different sweeteners; in this article, I will discuss the most common sweeteners, the research behind each one and their safety.


You have definitely heard about aspartame; it’s the most common sweetener used and can be found in most diet beverages. Aspartame is made up of two amino acids: phenylalanine and aspartic acid. High concentrations of phenylalanine can be found naturally in: soy, nuts, poultry and various meats. High concentrations of aspartic acid can be found naturally in: soy, nuts, eggs various meets. There is no reason or evidence to suspect that either of these is harmful to human health. Unless you have a condition known as Phenylketonuria (PKU), then neither of these amino acids will cause any problems. If you do have PKU, then you’ll have known from birth and not being able to consume sweeteners will be the least of your concerns.

Aspartame has been highly researched in both short-term and long-term studies on humans, rats, dogs and hamsters. There has been no data to link aspartame to any acute or long term adverse effects, even in high-dosages in any species studied. Subchronic studies have tested dosages of: 13 g/kg bw/d for 28 days, 10g/kg bw/d for 63 days and 6g/kw bw/d for 8 weeks and have found no adverse effects [2].

The FDA has approved an aspartame consumption of 50mg/kg bw/d. This means that a 150lb individual can consume 3400mg of aspartame per day; a diet coke has 125mg. Based on the FDA’s approved intake, this means that this individual could have 27 diet cokes per day. This person would be drinking almost 10L of purely diet coke to obtain this! It’s pretty safe to say that within normal consumption, it does not seem that aspartame will damage your health
Where to find it: Equal, NutraSweet, Walden Farms products, the majority of diet drinks,



Sucralose is non-nutritive sweetener that is most commonly found in Splenda and many low-calorie flavoured foods such as protein powders and bars, yogurts, diet drinks, Walden Farms and other low-calorie goods. Sucralose is made to imitate the taste of sucrose, or table sugar. However, is 600 times sweeter than sucrose.

Mann et al. (2000) observed the effects of giving sucralose to rats over an entire lifetime.3 The researchers gave rats a diet that comprised of either 0%, 0.3% or 3% of sucralose for 52 or 104 weeks [3]. After the allotted time, the researchers examined multiple organs (brain, heart, liver, kidneys, testes, ovaries, uterus, and many more) for toxicity and carcinogenicity. They found no adverse effects, or signs of toxicity or carcinogenicity in the rats who consumed sucralose every single day of their lives. The only difference was that the rats who consumed sucralose maintained a lower body weight. A human trial observed the effects of consuming 125mg for 3 weeks, 250mg for 4 weeks and 500mg of sucralose for 5 weeks. The researchers found no difference between the sucralose and placebo group [4]. Further, a recent review by Berry et al. (2016) specifically examined whether sucralose had a link to carcinogenicity. It was found that there is no evidence that sucralose has toxic or carcinogenic effects [5].

Based on the evidence, the FDA has approved a daily intake of 5mg/kg bw/d. One packet of Splenda contains 12mg of sucralose; meaning a 150lb person could have 28 packets of Splenda per day. Similar to aspartame, it seems that sucralose will not be harmful when consumed within normal ranges.


Stevia is a zero-calorie, natural herbal sweetener that is 250 times sweeter than table sugar. The sweetness in stevia comes from components called steviol glycosides. The US and European regulations only approve high quality Stevia leaf extracts that are at least 95% steviol glycosides. Thus, we must look at the research on steviol glycosides since the Stevia we consume is almost entirely made of this compound. Mostly, we must look at the effects of steviosides since they make up the majority of steviol glycosides

In a 104-week study, rats were exposed to a diet that was composed of either 0, 2.5 or 5% stevioside to assess the carcinogenicity of stevioside. There was no difference between groups and it was concluded that stevioside was not carcinogenic in this study [6].­ The Joint FAO/WHO Expert Committee on Food Additives saw this study as clear evidence that stevioside is non-carcinogenic [7]. Further literature has shown that stevioside could have a positive effect on people with hypertension and Type 2 Diabetes [8].

Based on these findings, the WHO has approved an ADI for steviol of 4mg/kg bw/d, which equates to 12mg/kg bw/d of pure Stevia Leaf Extracts that you would find in brands such as Truvia. A standard packet of Stevia-base sweeteners contains approximately 20mg of Stevia Leaf Extracts. Thus, a 150lb person would be able to consume approximately 40 packets of the sweetener per day.

The Short and Sweet:

In summary, there is no current evidence showing that regularly consuming a moderate amount of these sweeteners is harmful to your health. In fact, if sweeteners can help you achieve a healthy body level then it can be argued that they may help you become healthier. Keep in mind that I have reviewed the 3 most common sweeteners but there are many more; this article is not stating that all sweeteners are healthy in these amounts. It is your responsibility to search for other sweeteners you may wish to use and learn about their daily limits!

As for the sweeteners reviewed above, they are safe to consume and it is highly unlikely that their efficacy will be disproven. The overwhelming amount of evidence has shown that they are safe to use both in the short and long term… so enjoy your diet soda, sugar-free Jello and zero-calorie Syrups! If you’re craving something sweet, you don’t need to eat something that contains a large amount of sugar and calories. Instead, you can opt for something that has been artificially sweetened that can help you satisfy your craving while completely keeping you on track. As with most things, keep your consumption within moderation and you will be safe!


About the Author
Miguel is a bodybuilder, academic and FDL coach with a burning passion for science and fitness. He is studying Nutritional Biochemistry at McGill University, Canada, and has the goal of obtaining PhD in Exercise Science. Miguel’s purpose for obtaining an extensive education is to become the best coach possible and to contribute to the academic field by performing research on strength and physique athletes. Miguel has worked for top names in the industry such as: Dr. Layne Norton, Alan Aragon and Menno Henselmans

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1: Peters JC1, Wyatt HR, Foster GD, Pan Z, Wojtanowski AC, Vander Veur SS, Herring SJ, Brill C, Hill JO. The effects of water and non-nutritive sweetened beverages on weight loss during a 12-week weight loss treatment program. Obesity (Silver Spring). 2014 Jun;22(6):1415-21. doi: 10.1002/oby.20737. [PMED]

2: Kotsonis FN, Hjelle JJ. 1996. The safety assessment of aspar-tame: scientific and regulatory considerations. In: The Clinical Evaluation of a Food Additive: Assessment of Aspartame (Tschanz C, Butchko HH, Stargel WW, Kotsonis FN, eds). Boca Raton, FL:CRC Press, 23–41.

3: Mann SW, Yuschak MM, Amyes SJ, Aughton P, Finn JP. A combined chronic toxicity/carcinogenicity study of sucralose in Sprague-Dawley rats. Food Chem Toxicol. 2000;38 Suppl 2:S71-89. [PMED]

4: Berry C, Brusick D, Cohen SM, Hardisty JF, Grotz VL Williams GM. Sucralose Non-Carcinogenicity: A Review of the Scientific and Regulatory Rationale. Nutr Cancer. 2016 Nov 16; 68(8): 1247–1261. [PMED]

5: Berry C, Brusick D, Cohen SM, Hardisty JF, Grotz VL, Williams GM. Sucralose Non-Carcinogenicity: A Review of the Scientific and Regulatory Rationale. [PMED]

6: Toyoda K1, Matsui H, Shoda T, Uneyama C, Takada K, Takahashi M. Assessment of the carcinogenicity of stevioside in F344 rats. Food Chem Toxicol. 1997 Jun;35(6):597-603. [PMED]

7: Carakostas MC, Curry LL, Boileau AC, Brusick DJ. Overview: the history, technical function and safety of rebaudioside A, a naturally occurring steviol glycoside, for use in food and beverages. Food Chem Toxicol. 2008 Jul;46 Suppl 7:S1-S10. doi: 10.1016 [PMED]

8: Chan P1, Tomlinson B, Chen YJ, Liu JC, Hsieh MH, Cheng JT. A double-blind placebo-controlled study of the effectiveness and tolerability of oral stevioside in human hypertension. Br J Clin Pharmacol. 2000 Sep;50(3):215-20. [PMED]


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