Sugar-free energy drinks: what sweeteners are really worth the hype?
A "zero" can seems like the perfect compromise: energy without the sugar. Except that the sweet taste comes from somewhere, and the caffeine doesn't change by a single milligram. In this article, we'll look at what's really in a sugar-free energy drink, what health authorities say about sweeteners, and how to read a label in thirty seconds. No panic, no marketing, just facts.
What exactly is a sugar-free energy drink?
A sugar-free energy drink is a drink that replaces sugar with high-intensity sweeteners while keeping the same dose of caffeine and often the same other active ingredients as the regular version. In practical terms, you remove the calories from sugar, but not the stimulant. A 250 ml can typically contains around 80 mg of caffeine, whether sweetened or not.
Sugar-free, no added sugars, reduced: three different labels
These labels are governed by European Regulation 1924/2006 on nutrition claims. "Sugar-free" means the drink contains no more than 0.5 g of sugars per 100 ml. "No added sugars" means that no sugar or sweetening ingredient has been added, but the drink may contain sugars naturally present in fruit. "Reduced" indicates a reduction of at least 30% compared with a reference product.
The main thing to remember: none of these labels tell you whether the drink contains sweeteners. To find out, you need to read the ingredients list.
The sweeteners found in a sugar-free energy drink
The most common sweeteners in sugar-free cans are aspartame, acesulfame K, sucralose, and steviol glycosides. They are hundreds of times sweeter than table sugar, so only a tiny amount is needed. Manufacturers often combine two or three because each leaves a particular aftertaste, and the blend tastes more like sugar.
| Sweetener | Code | Sweetening power (approx.) | Good to know |
|---|---|---|---|
| Aspartame | E951 | 200 times sweeter than sugar | Acceptable daily intake of 40 mg per kg according to the EFSA; classified as "possibly carcinogenic" (Group 2B) by the IARC in 2023 |
| Acesulfame K | E950 | 200 times sweeter than sugar | Often combined with aspartame or sucralose to mask bitterness |
| Sucralose | E955 | 600 times sweeter than sugar | Very stable, common in drinks and powders |
| Steviol glycosides | E960 | 200 to 300 times sweeter than sugar | Stevia extracts, purified in a factory, with a licorice-like aftertaste |
| Sugar (for comparison) | None | Reference | About 4 kcal per gram; the WHO recommends staying below 10% of your intake from free sugars |
The word "natural" on a stevia product doesn't mean much: the permitted steviol glycosides are highly refined extracts. That's not a problem in itself; it's just useful to keep in mind when a can is marketed as "naturally sweetened."
Sweeteners: real danger or exaggerated fear?
At permitted doses, sweeteners in energy drinks are considered safe by the European Food Safety Authority (EFSA), but two recent opinions advise against making them an automatic daily choice. The issue deserves better than "it's poison" or "it's risk-free."
What the WHO and IARC have said since 2023
In May 2023, the World Health Organization issued a recommendation against using sweeteners for weight control, due to a lack of proven long-term benefits. In July 2023, the International Agency for Research on Cancer (IARC) classified aspartame in Group 2B, "possibly carcinogenic to humans," a category based on limited evidence.
That same month, the WHO and FAO's JECFA expert committee maintained the acceptable daily intake at 40 mg per kg of body weight. For a 70 kg person, that's far more aspartame than a can contains. So the message isn't "immediate danger," but "there's no reason to make it a habit just because it's zero calories."
The real trap: getting used to sweet flavors
A sugar-free can still tastes very sweet. If it replaces water in your day, your palate gets used to that level of sweetness and everything else seems bland. It's less a question of toxicity than of habit. Water remains the foundation of your hydration; an energy drink is an occasional boost, with or without sugar.
Sugar-free doesn't mean caffeine-free
A sugar-free energy drink contains the same amount of caffeine as its sugary version, so the consumption guidelines remain exactly the same. The EFSA estimates that a healthy adult can consume up to 400 mg of caffeine per day and up to 200 mg in a single dose without risk to their health. Two 250 ml cans containing 80 mg each, plus two coffees, and you're already approaching the limit.
The origin of caffeine matters to some people too: synthetic in most cans, and from plants such as guarana or mate in others. We explain these differences in our guide to natural and synthetic caffeine. And if you're wondering what the other star ingredient in cans does, we've also taken a closer look at the real role of taurine in energy drinks.
Sugar-free, low-sugar or classic: a comparison
The real difference between a classic can, a sugar-free version and a low-sugar drink with no sweeteners comes down to sugar and whether sweeteners are present, not caffeine. Here are the typical figures for a 250 ml can.
| Per 250 ml | Classic, sweetened | Sugar-free | Low in sugar, no sweeteners |
|---|---|---|---|
| Sugars | Around 25 to 28 g | 0 g | Around 5 to 8 g |
| Sweeteners | Rarely | Yes, often 2 or 3 | No |
| Calories | Around 110 kcal | Less than 10 kcal | Around 30 to 40 kcal |
| Caffeine | Around 80 mg | Around 80 mg | Varies, often around 80 mg |
| Taste | Very sweet | Very sweet | Lighter, fruitier |
The figures vary from brand to brand, which is exactly why it’s better to check rather than trust a logo. To compare cans side by side without relying on what brands say, the independent comparison tool drinkscore.info compares the caffeine, sugar and ingredients in energy drinks sold in Belgium and France.
How to read the label on a sugar-free energy drink
To assess a sugar-free energy drink, check three parts of the label: the ingredients list, the nutrition facts and the caffeine warning. It takes just thirty seconds.
1. The ingredients list
Look for the codes E950, E951, E955 and E960 or their full names. Ingredients are listed in descending order by quantity, so the earlier an ingredient appears, the more of it the recipe contains. Also look out for colourings and preservatives.
2. The nutrition facts
Check the “of which sugars” line per 100 ml, then multiply by 2.5 for a 250 ml can or by 5 for a 500 ml can. Many cans today are 500 ml, which doubles everything, including the caffeine.
3. The caffeine warning
When the caffeine content exceeds 150 mg per litre, European regulations require the label “high caffeine content” along with the amount in mg per 100 ml. Always calculate this figure for the whole can to know how much you’re really drinking.
Buddy's choice: a little sugar rather than sweeteners
At Buddy, we chose to keep a little sugar rather than add sweeteners, because we prefer a short ingredient list and a less sweet taste over a big, bold zero. Our natural organic energy drink contains 2.7 g of sugar and 13 kcal per 100 ml, with 80 mg of caffeine from organic guarana per 250 ml can, and no additives.
It’s not a sugar-free drink, and we’re not claiming it is. It’s a deliberate choice: around 7 g of sugar per can, about four times less than a regular can, without using aspartame or sucralose. If you want to try all four flavors, you can find them on the Buddy range page.
Key takeaways
A sugar-free energy drink saves you the sugar, not the caffeine. Approved sweeteners are considered safe at the recommended doses, but the WHO doesn’t recommend them for weight management, and aspartame is under review. Read the label, keep track of your caffeine intake throughout the day, make water your go-to drink, and choose the can that matches what you really want to avoid: sugar, sweeteners, or both.
Frequently asked questions about sugar-free energy drinks
Sugar-free energy drinks and weight gain: what’s the link?
A sugar-free energy drink contains very few calories, so it doesn’t directly cause weight gain. However, since 2023, the WHO has noted that sweeteners have not shown lasting benefits for weight control, making them a poor weight-loss aid.
What’s the maximum number of sugar-free energy drinks per day?
The guideline to follow is caffeine: the EFSA sets the limit at 400 mg per day for a healthy adult, and 200 mg in a single dose. With 80 mg per 250 ml can, two cans a day are already a reasonable upper limit if you also drink coffee or tea.
Which sweetener should you choose in an energy drink?
There’s no sweetener that’s clearly better than the others: aspartame, sucralose, acesulfame K, and steviol glycosides approved in Europe all comply with the acceptable daily intakes set by the EFSA. If you want to avoid them, choose a lightly sweetened drink without sweeteners, or simply water.
How does a sugar-free can affect your teeth?
A sugar-free can is still acidic, often because of citric acid, and this acidity can weaken tooth enamel even without sugar. Drinking through a straw, not sipping it for hours, and rinsing your mouth with water can limit the effect.
Why does a sugar-free drink taste so sweet?
Intense sweeteners are 200 to 600 times sweeter than sugar, so just a few milligrams are enough to create a very sweet taste. That’s what makes it possible to have zero sugar while keeping the same mouthfeel.
