Is Aspartame Dangerous? No, Here's why

By Aadam | Last Updated: December 10th, 2020

Aspartame is a popular artificial sweetener used to replace sugar in a number of foods and drinks–notably, diet drinks. It’s been met with a lot of controversy over its safety. In this article I’ll be explaining why, unless you’re a rat, you don’t have to worry about consuming aspartame.

In 1965, chemist James Schlatter was working on an anti-ulcer drug when, unbeknownst to him, he accidentally contaminated his finger with a white substance.

Later that day, Schlatter was sat reading and while licking his finger to turn the page, he noted the sweet taste of aspartame.

Little did he know that this serendipitous discovery would spawn an entire industry and a shitstorm that would divide the entire health and fitness industry.

Chances are, something like this has happened to you

But is it true? Will you die if you consume aspartame? Will it cause weight gain? Spike insulin? Cause cancer and the plethora of other maladies people claim? Well, let’s find out.

What is Aspartame?

Aspartame is a popular artificial sweetener used in many foods and drinks – most notably diet, or zero-calorie, sodas.

FYI: Coke cans are impossibly fucking hard to draw.

Contrary to popular belief, aspartame does contain calories: 4 calories per gram. However, seeing that aspartame is 200x sweeter than table sugar, the amount required to sweeten food is so small the calories are negligible – making it essentially “calorie-free”.

What’s With the Aspartame Hype?

In 2005, a study found more lymphomas and leukaemias in rats fed very high doses of aspartame. 1

So the media did this:

And people did this:


While there was a dose-response relationship between aspartame consumption and the prevalence of cancer, the rats were given an absurdly large amount: between 4 mg/kg all the way up to 5,000 mg /kg of bodyweight.

Let’s put this into context: an average rat weighed 400 grams (0.4kg).

But, hold on. Let’s apply these numbers to a human.


The FDA has set the acceptable daily intake (ADI) for aspartame at 50 mg/kg of bodyweight.

As the editors of point out:

But, Wait! There’s More

In 2002, “Aspartame: Review of Safety” was published in the monthly peer-reviewed scientific journal, Regulatory Toxicology and Pharmacology, concluding:

More than 30 years have elapsed since the foundations of today’s aspartame safety database were laid. Since that time the portfolio of studies assessing the safety of aspartame has continued to grow.

A search of the scientific literature on the U.S. National Library of Medicine’s MEDLINE reveals almost 700 citations for aspartame with a number of these relevant to aspartame safety.

The extensive body of research undertaken on aspartame clearly and overwhelmingly demonstrates its safety for its intended use.

The aspartame safety data have been evaluated and found satisfactory by regulatory scientists in all major regulatory agencies and expert committees, including the U.S. Food and Drug Administration (FDA), the EU Scientific Committee for Food (SCF), and the Joint FAO/WHO Expert Committee on Food Additives (JECFA).

Further, aspartame has been approved for human consumption by regulatory agencies in more than 100 countries and received wide consumer acceptance with consumption by hundreds of millions of people over the past 20 years, representing billions of man-years of safe exposure.” 

Read that last paragraph (that I’ve bolded ) again: consumption by hundreds of millions of people over the past 20 years, representing billions of man-years of safe exposure.”

If aspartame was killing us, we’d know by now because there would be a bunch of dead people whose deaths would be linked back to aspartame, but there isn’t. Wanna know why? Because it’s safe.

But, I’m not done yet.

In 2006 researchers from the National Cancer Institute looked at cancer rates in more than 500,000 older adults. 2

One last thing because ‘OMG, CHEMICALS’.

When you consume aspartame…

…the body breaks it down into its constituent parts.

Aspartic acid and phenylalanine are amino acids and can be found in most sources of dietary protein. In fact, the amount of aspartic acid and phenylalanine found in food-based sources of protein far exceeds the amount found in aspartame.

Methanol tends to be the one people lose their shit over, and yes, methanol can be a hazard as it’s converted to formaldehyde in the body – a known carcinogen. HOWEVER, the dose makes the poison, and the amount found in aspartame is completely safe. Additionally, methanol is also found in fruits and vegetables.

Aspartame and Weight Gain

Some people will vehemently argue that aspartame causes weight gain.

Firstly, this makes zero fucking sense because, as I noted earlier – aspartame is essentially calorie-free.

You’d have to consume an impossible amount of diet drinks for it to have an impact on your weight, and seeing as you’d die from water intoxication first weight gain would probably be the least of your worries.

Secondly, research disagrees with this idea. 

In one study, 41 overweight men and women were split into two groups. 3

Guess what happened? That’s right: the group consuming the sucrose supplement – you know, the one that contained calories – saw increases in energy intake, body weight, fat mass, and blood pressure; while “these effects were not observed in a similar group of subjects who consumed artificial sweeteners.” Because that’s what happens when you control calorie intake.

To add, in another six-month long randomised clinical trial, researchers had participants replace caloric beverages with noncaloric beverages.

And, once again, participants that replaced caloric beverages with noncaloric beverages lost weight. 4


So then why do people think aspartame causes weight gain?

False correlations. People who drink calorie-free drinks tend to fall for the Health Halo of Food effect: they assume because they’re drinking zero-calorie drinks they can eat more food.

This leads them to consume a greater number of calories and gaining more weight (and fat). People then make a faulty correlation between the two: “Diet drinks cause weight gain”, instead of, “People end up eating more calories leading them to gain more weight”.

Does Aspartame ‘Spike Insulin’?

No. It doesn’t. There is zero evidence to suggest that aspartame spikes insulin levels–in both healthy and diabetic individuals.

In a 2018 study, researchers assigned 100 participants to one of three groups for 12 weeks. 5

Researchers concluding:

“Aspartame ingested at 2 doses for 12 wk had no effect on glycemia, appetite, or bodyweight among healthy, lean adults. These data do not support the view that aspartame is problematic for the management of glycemia, appetite, or body weight.”

And in a 2010 review, the Academy of Nutrition and Dietetics concluded that artificial sweeteners “Do not affect glycemic response in people with diabetes mellitus.” 6

The only studies that have found aspartame to spike insulin were done on, surprise surprise, rats. Aa

Even if it did spike insulin–it doesn’t, but if it did in some alternate reality–so what?

Insulin spikes are a perfectly normal function of a perfectly normal and healthy functioning body.

Even protein spikes insulin.

And if you’re still subscribing to the “insulin causes fat gain” dumbfuckery – it’s time you updated your factz. Yeah, with a Z, because fuck you I do what I want.

Take-Home Points

1. There are over 200 studies that confirm aspartame to be safe for human consumption.

1a.If you believe that the Illuminati or some dark secret society is trying to poison you, I suggest you stop watching conspiracy theories on YouTube. I mean, I’m no Illuminati expert but I’m pretty sure a bunch of old rich billionaires have more important things to address than poisoning people through Diet Coke.

2. Unless you’re a rat and/or injecting diet drinks straight into your blood, you have nothing to worry about from consuming aspartame-based foods and beverages.

3. The only real concern is that diet drinks can rot your teeth if consumed in large amounts.

3a. If you have the extremely rare, genetic disorder phenylketonuria then you should avoid aspartame. If you are suffering from a super rare disorder you probably already know this but seeing as people were losing their shit over me not putting this point here, I’m putting this point here.

4. There is some emerging research that aspartame can have a negative impact on the gut microbiome. This is still up for debate and I’ll hazard a guess that as long as you’re not being a complete dumbfuck with your consumption of artificial sweeteners, you’ll be fine. Danny Lennon did a great podcast on that topic and artificial sweeteners in general, here.

5. While there aren’t any studies confirming this, anecdotally, some of my clients have noted that drinking diet drinks tend to increase “sugar cravings”. If this happens to you, then simply don’t drink them or reduce your intake.

6. Constantly consuming really sweet food and drink changes your taste palate. I know people who can’t drink plain water as they don’t “like the taste” and need to sweeten everything. This isn’t exactly ideal.

7. Aspartame doesn’t spike insulin levels and ‘trick your body into storing fat’. On the contrary, it can aid fat loss due to helping you reduce and control your calorie intake.

7. Once again, don’t be an idiot with these things and you’ll be fine.

8. Drink more goddamn water.

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