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Diet Beverages & Artificial Sweeteners – The Scientific Truth (It May Surprise You)

artificial sweetners
25982611 - helsingborg, sweden - january 21, 2014: 0,33l assorted coca-cola cans isolated on white background. coca-cola is a carbonated soft drink sold in shops, restaurants, and vending machines around the globe.

There’s a hot debate whether diet beverages or soda and artificial sweeteners are healthy or dangerous.

It’s no wonder that so many people are confused (including myself) with some authorities recommending their intake over the high sugar versions, while a lot of other gurus state they are extremely unhealthy and a chemical storm that will wreck your health and cause disease.

As always, there isn’t one clear-cut answer and the issue is often debated based on ‘opinions’ or the latest meme that goes viral on FB rather than hard, honest well-designed research studies or controlled science.

In this article, I’ll dive into the honest research regarding diet soda and artificial sweeteners and whether or not they play a role (both positive and negative) in obesity and even health.

I guarantee some of the answers may surprise you. Here’s the bittersweet truth…

Diet Soda & Artificial Sweeteners – Good, Bad or the Devil?

Artificial sweeteners come in many different forms but the most popular typically include aspartame (Equal), sucralose (Splenda) and saccharin (Sweet’N Low).

The use of these sweeteners actually dates all the way back to the 1800s when saccharin was accidentally synthesized (1).

These artificial sweeteners have become a staple in our diets due to the attempt to reduce excess sugar intake and the fact they are far sweeter than actual sugar, while contributing very few or even no calories.

Despite the fact they can reduce sugar intake and lower total calorie intake, aiding in weight loss, many people still see them as unhealthy.

This is partly due to the belief that consuming them induces similar hormonal and brain responses to that of sugar, in addition to potentially being associated with increased risk of disease states such as cancer. But, what does the actual science say?

‘Negative’ Research on Diet Soda & Artificial Sweeteners

Anything is dangerous in the right dose, even water. Yep, that’s right … Here are two examples:

  • Firstly, a 28 year old woman in the USA died after drinking six liters of water in a 3 hour period for a contest, dying later that day from water intoxication.
  • In 2005 a study published by the New England Journal of Medicine found that around 16% of marathon runners developed some level of dangerous hyponatremia, or dilution of the blood caused by drinking too much water.

So, before we continue, my question to you is, just because water can kill you in high doses, does that mean that a normal intake, i.e. 2-4 liters per day is also unhealthy?

Clearly the answer is no, it’s basic logic. However, this EXACT principle applies to diet soda and sweeteners (see the example below), although most people (especially the ones who dislike it) tend to ignore this fact.

When it comes to the limited research regarding human subjects and artificial sweeteners, there is some correlative data (i.e. weak data that draws conclusions over years) indicating that consuming artificial sweeteners may increase the risk of developing metabolic syndromes, leading to increased risk of diabetes and obesity (2, 3).

Unfortunately as with any research, the devil is in the details. Along with artificial sweeteners, the study also found associations with typical western diet staples such as meat (which we know is healthy) and fried foods.

To conclude that artificial sweeteners are a reason for obesity based on this study is speculative at best, since there are so many other factors that may be contributing.

In essence, there is in fact research associating artificial sweeteners with an increased risk of obesity, but it’s not a direct relationship. It’s a relationship confounded by many other factors that certainly contribute to obesity and negative health, rather than simply consuming artificial sweeteners.

In the world of research and science, these types of studies are often ignored and not classed as ‘real, controlled research’.

Additionally, there is some negative research regarding artificially sweetened beverages and cancer. Although there is one catch. The studies are done using rats (but again, all the people who hate diet soda or sweeteners tend to ignore this fact).

Of course, the big issue with these studies is that they simply point us in the right direction from a biological standpoint, but not direct cause and effect; more often than not, what happens in a rat does not translate to humans.

Often the effects of substances vary widely when given to humans compared to rats. Artificial sweeteners are one of these cases.

Despite the fact that some research has indicated that artificial sweeteners like aspartame are linked to cancer in mice, the doses which would be required to do so in humans would be astronomical.

For instance, the FDA has set safe daily consumption of substances like aspartame to 50 milligrams per kilogram of body weight (4, 5).

For a 90 kg (200 lb) individual that would be the equivalent of consuming 25 cans of artificially sweetened soda per day and would still be considered within a safe range.

Diet Soda & Artificial Sweeteners Cause Weight Gain – False Science?

At its most fundamental level, it’s impossible for artificial sweeteners to directly contribute to weight gain; it’s basic science and the laws of thermodynamics.

In fact, artificial sweeteners are often used in order to reduce calorie intake and thus help reduce body weight. However, many people still insist that artificial sweeteners induce an insulin response, similar to what happens when you consume sugar in one form or another.

As a result of this insulin spike, it is theorized this leads to a metabolic disorder called insulin resistance, which means that insulin isn’t able to do its job of removing glucose from the blood and storing it in various tissues of the body.

In theory, when this occurs, it can lead to further disease states such as type 2 diabetes and obesity.

Unfortunately for proponents of this incorrect theory, research has determined that artificial sweeteners such as aspartame don’t induce an insulin spike, despite claims.

Even if they did, a small insulin spike would not match that of an insulin spike from regular sugar, soda, ice cream, pizza etc. It’s these foods consumed over years which cause weight gain and insulin resistance, not sweetener or diet soda (6, 7, 8, 9).

Additionally, in a groundbreaking study on evaluating the use of artificial sweeteners versus just water when attempting to lose weight, the researchers revealed that consumption of artificial sweeteners was actually associated with greater weight loss and a greater ability to keep the weight off after the diet (10).

It’s very likely that consuming artificially sweetened beverages such as diet soda may satisfy sweet cravings without providing the additional calories, leading to weight loss.

Does this mean that diet soda is better than water? No, but it doesn’t appear to be worse in sensible moderation (just like water). Because it has no calories, it simply can’t cause weight gain, it’s physically and biologically impossible.

So What’s The Conclusion About Diet Soda & Artificial Sweeteners?

As it turns out, there probably isn’t any issue with consuming artificially sweetened beverages such as diet soda on a regular basis in moderation.

Research that has shown negative effects is fairly weak, most of it being done in rats not humans and even that has many other factors affecting the outcome, making it impossible to blame artificial sweeteners (2).

Furthermore, other research showing associations with artificial sweeteners and cancer is carried out on rats and still very early. Next, these findings are done at crazy doses that equate to say 200 cans of diet soda per day, so they are far from realistic or unbiased (4).

Lastly, research on artificial sweeteners for weight loss actually indicates a beneficial effect overall, such as reduced body weight, rather than the commonly held misbelief that they lead to weight gain. If you know even the basics of fat loss and metabolism you will clearly understand how it’s physically impossible for a zero calorie product to cause weight gain.

Despite outlandish claims from people with unbiased agendas or the ‘clean eating gurus’, artificially sweetened diet sodas are safe for you to consume and even advised if your goal is to reduce calories and body weight.

Take Home Key Points on Diet Soda & Artificial Sweeteners

Firstly, the key point is to understand that there’s not any real, strong research in a controlled setting to show ill health from a sensible dose of artificial sweeteners in humans.

Sadly, like many aspects of nutrition, it’s very easy for people with hidden agendas to twist the research or churn out random ‘facts’ that have no real evidence at all. Of course, any new meme or video always goes viral, but it doesn’t mean it’s true.

Now, am I advising you to consume artificial sweeteners or diet soda? No, but equally, should you not consume it and avoid it, if you do enjoy it? No, absolutely not.

Like everything, it depends on you. If you love it, then go ahead, it probably will help you consume fewer calories, it may reduce cravings and may actually aid in hydration (remember it’s around 98% water).

If you think that diet soda or artificial sweeteners are bad or unhealthy because they’re not natural, then you should maybe spend some time reading the science to become less biased. Of course, I will be the first to say we should focus on natural whole foods 80% of the time, but drinking the odd diet soda or using a normal intake of artificial sweeteners is also perfectly fine.

In summary, diet soda or artificial sweeteners are perfectly ok in a moderate dose, just like water. If you still want to say it’s unhealthy because rats got ill from taking in the equivalent of 200 servings per day, well you should probably not drink water either because 200 servings of water would have killed the rats far quicker than the artificial sweetener.

As with everything, remember to actually check the research and don’t trust the internet fitness/health gurus who don’t understand or even know how to read a research study…


  1. The Pursuit of Sweet. (2017, March 06). Retrieved June 14, 2017, from https://www.chemheritage.org/distillations/magazine/the-pursuit-of-sweet
  2. Lutsey, P. L., Steffen, L. M., & Stevens, J. (2008). Dietary intake and the development of the metabolic syndrome. Circulation, 117(6), 754-761.
  3. Nettleton, J. A., Lutsey, P. L., Wang, Y., Lima, J. A., Michos, E. D., & Jacobs, D. R. (2009). Diet soda intake and risk of incident metabolic syndrome and type 2 diabetes in the Multi-Ethnic Study of Atherosclerosis (MESA). Diabetes care, 32(4), 688-694.
  4. National Toxicology Program. (2005). NTP report on the toxicology studies of aspartame (CAS No. 22839-47-0) in genetically modified (FVB Tg. AC hemizygous) and B6. 129-Cdkn2atm1Rdp (N2) deficient mice and carcinogenicity studies of aspartame in genetically modified [B6. 129-Trp53tm1Brd (N5) haploinsufficient] mice (feed studies). National Toxicology Program genetically modified model report, (1), 1.
  5. Center for Food Safety and Applied Nutrition. (n.d.). Food Additives & Ingredients – Additional Information about High-Intensity Sweeteners Permitted for use in Food in the United States. Retrieved June 14, 2017, from https://www.fda.gov/food/ingredientspackaginglabeling/foodadditivesingredients/ucm397725.htm
  6. Møller, S. E. (1991). Effect of Aspartame and Protein, Administered in Phenylalanine‐Equivalent Doses, on Plasma Neutral Amino Acids, Aspartate, Insulin and Glucose in Man. Basic & Clinical Pharmacology & Toxicology, 68(5), 408-412.
  7. Wolf-Novak, L. C., Stagink, L. D., Brummel, M. C., Persoon, T. J., Filer, L. J., Bell, E. F., … & Krause, W. L. (1990). Aspartame ingestion with and without carbohydrate in phenylketonuric and normal subjects: effect on plasma concentrations of amino acids, glucose, and insulin. Metabolism, 39(4), 391-396.
  8. Horwitz, D. L., McLane, M., & Kobe, P. (1988). Response to single dose of aspartame or saccharin by NIDDM patients. Diabetes care, 11(3), 230-234.
  9. Teff, K. L., Devine, J., & Engelman, K. (1995). Sweet taste: effect on cephalic phase insulin release in men. Physiology & Behavior, 57(6), 1089-1095.
  10. Peters, J. C., Beck, J., Cardel, M., Wyatt, H. R., Foster, G. D., Pan, Z., … Hill, J. O. (2016). The effects of water and non-nutritive sweetened beverages on weight loss and weight maintenance: A randomized clinical trial. Obesity (Silver Spring, Md.), 24(2), 297–304. http://doi.org/10.1002/oby.21327​

About the author

Rudy Mawer, MSc, CISSN

Rudy has a 1st class BSc in Exercise, Nutrition & Health and a Masters in Exercise & Nutrition Science from the University of Tampa. Rudy currently works as a Human Performance Researcher, Sports Nutritionist and Physique Coach. Over 7 years he has helped over 500 people around the world achieve long last physique transformations.

He now works closely with a variety of professional athletes and teams, including the NBA, USA Athletics, World Triathlon Gold Medalists, Hollywood Celebrities and IFBB Pro Bodybuilders. If you would like to get in contact or work with Rudy please contact him on social media.

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