Energy drinks: what's in the can and where the effect comes from
The composition of an energy drink looks impressive: taurine, glucuronolactone, inositol, B vitamins, and guarana extract. However, the effect is driven by two components from the list, both of which are well-known: caffeine and sugar. The rest either enhance the former or are present in amounts that do not make a difference.
What actually works
Caffeine. The main active component. A 250 ml can usually contains about 80 mg — roughly the same as a cup of coffee. The 450–500 ml cans, which are sold more frequently, contain twice as much accordingly.
Sugar. The regular version contains about 25–30 g per 250 ml, which is 5–6 teaspoons. This provides a quick glucose spike and a subjective feeling of a boost, which is often followed by a crash.
Guarana is not a separate component, but a second source of the same caffeine, and its content must be added to the stated amount.
What is in the ingredients but provides no effect
- Taurine. An amino acid that is synthesized in the body and obtained from regular food. There is no convincing evidence that taurine supplementation in these amounts provides an energizing effect.
- B vitamins. They are involved in energy metabolism, but in the absence of a deficiency, additional intake does not add energy. The difference between supplements and medications is analyzed in the article about dietary supplements.
- Glucuronolactone, inositol. They are present in the composition, but no independent contribution to alertness has been demonstrated.
Practical conclusion: the effect of an energy drink is replicated by a cup of coffee with sugar, and this is a convenient benchmark for comparison.
How much is this per day
The caffeine guideline for a healthy adult is up to 400 mg per day and no more than about 200 mg at a time; for pregnant women, it is lower, and this is a question for a doctor. More details can be found in the article about coffee.
Two 500 ml cans use up the entire daily guideline, and if coffee and tea are added to them, it is exceeded. Caffeine must be counted from all sources at once, including soda.
Calories
| Volume | Regular version | Sugar-free version |
|---|---|---|
| 250 ml | about 110 kcal | about 5 kcal |
| 500 ml | about 220 kcal | about 10 kcal |
As with soda, these calories are not perceived as food and are almost never entered into a food diary — the mechanism is analyzed in the article about calorie counting apps.
Why the combination with alcohol is highlighted separately
Caffeine reduces the subjective feeling of intoxication without affecting its objective level. A person feels soberer than they actually are, and this leads to consuming more and making decisions they would not have made otherwise.
It is also worth remembering the calorie content of the alcohol itself — the article about calories in alcohol.
Who should abstain
- children and adolescents — daily caffeine guidelines for them are significantly lower than for adults;
- during pregnancy and breastfeeding;
- those with heart rhythm disorders, high blood pressure, or anxiety disorders — consult a doctor;
- those with sleep problems: caffeine is eliminated slowly, and an evening can affects the night;
- during intense physical activity in the heat — the combination with dehydration is discussed in the article about water and electrolytes.
What to keep in mind
- Look at the volume, not the can. 500 ml is two servings of caffeine.
- Add guarana to the stated caffeine.
- Do not use instead of sleep. Caffeine masks fatigue rather than eliminating it; the link between sleep deprivation and appetite is in the article about sleep deprivation.
- Account for sugar. A can of the regular version is comparable to soda in terms of sugar.
Frequently asked questions
- How much caffeine is in an energy drink?
- About 80 mg in a 250 ml can — roughly the same as in a cup of coffee — and twice as much in a 500 ml can. Guarana in the ingredients is an additional source of the same caffeine, and its contribution is added to the stated amount.
- What provides the effect in an energy drink?
- Caffeine and sugar. Taurine, B vitamins, glucuronolactone, and inositol are present in the composition, but they have not been shown to contribute independently to alertness in these amounts.
- How many calories are in an energy drink?
- About 110 kcal in a 250 ml can of the regular version and about 220 in a 500 ml can, almost all of which is sugar. In sugar-free versions, there are only a few kilocalories.
- Why shouldn't energy drinks be mixed with alcohol?
- Caffeine reduces the subjective feeling of intoxication without affecting its objective level. A person feels soberer than they actually are, which leads to consuming more alcohol.
- Who should avoid energy drinks?
- Children and adolescents, pregnant and breastfeeding women. In cases of heart rhythm disorders, high blood pressure, and anxiety disorders, the matter should be discussed with a doctor. If you have sleep problems, keep in mind that caffeine is eliminated slowly.
Read next
- Coffee: how much you can drink and what adds calories — There are three questions about coffee, and they are different: how much caffeine is safe, does coffee harm your health, and why a latte with syrup costs as much as a full meal.
- Soda and its "zero": what changes when sugar is removed — The difference between regular soda and its "zero" version comes down to one line in the ingredients: a sweetener instead of sugar.
- Calories in alcohol: how many calories are in beer, wine, and spirits — Alcohol is the only category that almost everyone skips when counting calories.
This article is for general information. It is not medical advice, a diagnosis, or a prescription for treatment or a diet, and it does not replace a consultation with your doctor. If you have a health condition, are pregnant, take medication, or follow a diet prescribed to you, decisions about food belong with your doctor.
Figures from regulations, guidelines and studies are given as they stood when this article was prepared and may since have changed; check them against the primary sources. This article is not advertising, an offer, or individual advice, and neither the author nor the site owner is responsible for decisions taken on the basis of it.