Do diet sodas make you fat?

How many times have you been at a fast-food restaurant, ordered a value-sized meal and then justified it (at least a little bit) by drinking a diet soda?

If so, you’re certainly not alone. It’s estimated that about one-fifth of the U.S. population consumes diet drinks on any given day.  

Most of us who have ever tried to lose weight have probably heard that we should avoid “drinking our calories,” so choosing a zero-calorie beverage like a Diet Coke would seem to make perfect sense.

But at the same time, we hear these horror stories online about how all of the chemicals in these diet drinks can make you gain weight, crave sugar, mess with your gut bacteria, and potentially lead to stroke, heart disease, and even an early death.

But is any of this true?

However, before we dig into this, we should probably figure out if it’s safe to be drinking these artificially sweetened beverages at all.

Are artificial sweeteners bad for you?

I’ll be honest and tell you that I’m not that crazy about most of the diet sodas out there because, to me, they have always had that odd chemical aftertaste, but honestly, that might just be in my head.

Admittedly, artificial sweeteners have gotten a lot better over the years. Despite my youthful appearance, I’m old enough to remember when Diet Coke first came out in 1982. Even before that, I remember drinking Tab and Pepsi Light (which had a weird lemony flavor) once in a while because they were the only soft drinks my grandma kept in her house.

Despite what you may have read online, actual scientific research has repeatedly proven that artificial sweeteners are safe to consume in the amounts that humans (not lab rats) typically consume them. There’s actually been a lot of research done on this topic. If you’re interested in diving in and learning more about it, I would suggest starting here or here.

Do diet sodas make you crave sugar?

So even though diet drinks may be safe to drink, what’s the point of ordering a Diet Coke if it’s just going to end up making you eat more and gain weight?

Even before the internet was a thing, you would often hear about how these artificial sweeteners can mess with your brain chemistry and cause you to gain weight because your body will start to crave sugar (more so than usual). 

Do diet sodas make you crave sugar?

The theory is that because these drinks taste sweet but don’t actually have any calories, your body somehow feels “tricked” and will start to crave sugary junk food to get the calories that it’s missing. 

However, research has shown that drinking diet soda is far more likely to make you crave less sugar rather than more.

These studies have found that when you eat a food with a certain taste profile such as sweet, salty, bitter, etc… you will crave less of that particular type of food immediately afterward.

This makes a lot of sense if you think about it. 

If you eat an ice cream sundae, you probably won’t be craving a piece of pie afterward. In other words, once you’ve satisfied a particular food craving, it’s unlikely that you will be craving more of it (at least for a few hours).

This is where drinking diet sodas/teas/juices can help you satisfy these sweet cravings and potentially help you lose weight.

Satisfying your sweet tooth

One study found that drinking an artificially sweetened juice reduced the desire to eat sweet foods more than drinking water alone.  

This means that if you have a sweet (but calorie-free) beverage with your meal such as a diet soda, you will be less likely to eat other sweet food in the same meal.

Unfortunately, this doesn’t mean that you won’t eat some other type of food instead.

This is why even after you have eaten a big meal, you may still have room for dessert because your “sweet” craving hasn’t yet been satisfied.

Do artificial sweeteners cause you to gain weight?

How many times have you heard the story about how a friend of a friend of someone’s cousin once gained a bunch of weight, and all she drinks is Diet Coke.

Then they go on about something they read in a magazine or saw online about how the chemicals in the artificial sweeteners destroy your metabolism or trick your body into retaining fat.

When you think about this, however, is this because diet drinks make you fat, or is it that overweight people are more likely to be the ones drinking diet drinks in the first place?

The Academy of Nutrition and Dietetics notes that although some observational studies report that people who use NCS [non-caloric sweetners] are more likely to gain weight, this does not mean that NCS cause weight gain, but rather that NCS are more likely to be consumed by people are overweight. 

This is one of those times you should not confuse correlation with causation.

In other words, just because overweight people are the ones drinking the diet sodas, that doesn’t mean that is how they became overweight in the first place.

Will drinking diet soda lead to an early death?

If causing you to gain weight and deal with uncontrollable sugar cravings wasn’t bad enough, you may have also heard that these diet drinks can increase the risk of stroke, heart disease, or even premature death.

A few years ago, a study came out that discovered people who drank diet drinks were 26% more likely to die prematurely than those who didn’t.

A similar large study found that artificially sweetened beverages led to an increased risk of stroke and heart disease

While these studies’ results may seem a little alarming at first, when we take a step back and think about it, this argument has the same problems as the weight gain issue.

Do diet drinks cause weight gain, strokes, heart disease, and an early death? Or is it the fact that overweight people who drink lots of diet sodas are more prone to these diseases because they don’t eat healthy foods, see their doctor, manage their stress, or get regular exercise?

In other words, diet drinks aren’t necessarily causing these problems. It’s that the people who choose to drink them have created these issues by their unhealthy lifestyle.

Artificial vs. Natural

Finally, I think a lot of this suspicion on artificial sweeteners comes from the fact that they are made in a lab and not found in nature. 

I’ll admit that I’m as guilty of this as anyone.

After all, how many times were we told over the years that trans-fat was completely harmless until science proved otherwise?  

At the same time, we shouldn’t fall into the trap that says all “natural” products are good and all man-made products are bad for you.

After all, what exactly does it mean to be natural?

Even though aspartame is created in a lab, it is made by combining two naturally occurring amino acids: phenylalanine and aspartic acid. It is then combined with methanol, which is commonly found in the foods we eat. 

Wait, isn’t methanol toxic?!

It’s true that methanol (wood alcohol) can be toxic to humans in large amounts, but then again so are a lot of other things that we eat every day. For example, many people don’t realize that methanol is naturally found in fruit and other types of foods.

In fact, you would consume more methanol drinking a glass of orange juice or eating a banana than you would from a can of Diet Coke. That’s not to suggest that you stop eating fruit and only drink diet soda to limit your methanol consumption. It’s that we are getting worked up over something that really isn’t an issue.

The bottom line:

Despite what you may have read in a magazine or on the internet, artificial sweeteners like Aspartame (used in Diet Coke), Acesulfame Potassium (Ace K used in Coke Zero), and Sucralose (Splenda) have been proven safe to consume in the amounts normal people would consume them.

Research has also shown that diet drinks will not stimulate your sweet tooth or make you crave more sweet foods in general.

In fact, drinking artificially sweetened beverages during a meal may help reduce the overall amount of food you eat, helping you lose weight.

Finally, although diet drinks have been associated with some negative health conditions such as stroke and heart disease, this is probably more of a reflection on the current health conditions of the people who choose to drink them rather than the drinks themselves. 

What do you think?

Are you a fan of diet drinks and think this whole issue has been blown out of proportion, or do you think we are better off sticking with sugar in our drinks and reducing our calories elsewhere? Take a moment to share your thoughts with us in the comment section below!


Fitch C, Keim KS. Position of the Academy of Nutrition and Dietetics: Use of Nutritive and Nonnutritive Sweeteners. J Acad Nutr Diet 2012; 112:739-58.

Magnuson BA, et al. “Aspartame: a safety evaluation based on current use levels, regulations, and toxicological and epidemiological studies.” Crit Rev Toxicol. 2007;37(8):629-727.

Mossavar-Rahmani Y, Kamensky V, Manson JE, et al. Artificially Sweetened Beverages and Stroke, Coronary Heart Disease, and All-Cause Mortality in the Women’s Health Initiative [published correction appears in Stroke. 2019 Jun;50(6):e176]. Stroke. 2019;50(3):555-562.  

Mullee A, Romaguera D, Pearson-Stuttard J, et al. Association Between Soft Drink Consumption and Mortality in 10 European Countries. JAMA Intern Med. 2019;179(11):1479–1490.

Rogers et al. “Sweet satiation: acute effects of consumption of sweet drinks on appetite for and intake of sweet and non-sweet foods.” Appetite. 149: June 1, 2020  

Phelan S, et al. “Use of artificial sweeteners and fat-modified foods in weight loss maintainers and always-normal weight individuals.” Int J Obes (Lond). 2009;33(10):1183-1190.

Stamataki, Nikoleta S, et al.  “Stevia Beverage Consumption prior to Lunch Reduces Appetite and Total Energy Intake without Affecting Glycemia or Attentional Bias to Food Cues: A Double-Blind Randomized Controlled Trial in Healthy Adults,” The Journal of Nutrition, Volume 150, Issue 5, May 2020, Pages 1126–1134,

Drew Kimble CSCS*D, CPT
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