A 16 oz (473 ml) energy drink typically has 70–240 mg of caffeine and, if regular, 54–62 g of added sugar, about 215–250 kcal from sugar alone. EFSA considers up to 400 mg of caffeine a day and 200 mg at once safe for healthy adults; children and pregnant women need much lower limits.
Key takeaways
- A 16 oz energy drink has 70–240 mg of caffeine; a small shot has 113–200 mg (NCCIH).
- Regular versions can contain 54–62 g of added sugar, about 215–250 kcal and more than WHO's daily sugar guide.
- EFSA: up to 400 mg caffeine a day and 200 mg at once is safe for healthy adults, 200 mg a day in pregnancy.
- Children and teens should stay under 3 mg of caffeine per kg body weight a day.
- Mixing energy drinks with alcohol masks drunkenness and is linked to heavier drinking.
What is actually in an energy drink?
Most energy drinks combine three things: caffeine, sugar (or sweeteners) and a mix of other ingredients such as taurine, guarana, B vitamins, ginseng or glucuronolactone. The caffeine and the sugar do most of the work you feel. Guarana is a plant source of caffeine, so it adds to the total even when the label lists caffeine separately.
They come in two main forms, according to the US National Center for Complementary and Integrative Health (NCCIH): cans similar in size to soft drinks, often 16 oz (473 ml), and small "energy shots" of 2–2.5 oz (60–75 ml) of concentrated liquid.
How much caffeine do energy drinks contain?
The range is wide, and in some countries the label does not have to state the exact caffeine content. NCCIH gives these typical amounts:
| Drink | Typical caffeine |
|---|---|
| Energy drink, 16 oz (473 ml) | 70–240 mg |
| Energy shot, 2–2.5 oz (60–75 ml) | 113–200 mg |
| Brewed coffee, 8 oz (240 ml) | about 100 mg |
| Cola, 12 oz (355 ml) | about 35 mg |
So a large energy drink can contain anything from less than a cup of coffee to well over two cups, and a tiny shot can match a large coffee in a few sips. That speed is part of the problem: it is easy to stack two drinks, or a drink and several coffees, without noticing the total.
How much caffeine is safe?
The European Food Safety Authority (EFSA) reviewed caffeine safety for healthy people in 2015. Its conclusions are a useful benchmark:
| Group | Intake EFSA considers safe |
|---|---|
| Healthy adults, single dose | up to 200 mg (about 3 mg per kg body weight) |
| Healthy adults, whole day | up to 400 mg, spread across the day |
| Pregnant or breastfeeding women | up to 200 mg a day |
| Children and teenagers | up to 3 mg per kg body weight a day |
For a 50 kg (110 lb) teenager, 3 mg per kg is 150 mg a day, which a single large can may exceed. EFSA also notes that single doses of 100 mg may affect sleep in some adults, especially close to bedtime. Caffeine sensitivity varies, and people with heart conditions, high blood pressure, anxiety or who take certain medicines should ask a doctor what is safe for them.
How many calories and how much sugar?
A regular 16 oz energy drink may contain 54–62 g of added sugar, according to NCCIH. Since sugar has 4 kcal per gram, that is about 215–250 kcal from sugar alone, all in a drink that does little to fill you up.
| Drink | Sugar | Calories from sugar |
|---|---|---|
| Regular energy drink, 16 oz (473 ml) | 54–62 g | about 215–250 kcal |
| Regular energy drink, 250 ml can (same sugar per ml) | about 29–33 g | about 115–130 kcal |
| Sugar-free energy drink | 0 g, sweeteners instead | close to zero |
The WHO advises keeping free sugars below 10% of daily energy, which is about 50 g on a 2,000 kcal day. One large regular energy drink can use up the whole day's allowance. Sugar-free versions remove most of the calories but not the caffeine. The guide to artificial sweeteners explains what is known about them, and sugar limits and hidden sources puts the numbers in context.
Do energy drinks affect weight loss?
Mostly through the calories. One regular can a day at around 230 kcal adds up to about 1,600 kcal over a week, which is a large slice of a typical weekly deficit. Liquid calories also tend not to reduce what you eat later, so they add on top of meals rather than replacing them. The guide to liquid calories shows how quickly drinks add up.
Energy drinks are not a fat-loss tool. Caffeine can make you feel more alert and may improve endurance during exercise, but there is no good evidence that the extra ingredients help with weight loss. Sleep matters too: caffeine late in the day can cut sleep short, and poor sleep is linked to more hunger the next day.
Are energy drinks useful before exercise?
Caffeine is one of the better-studied performance aids. NCCIH notes that energy drinks have been shown to improve endurance, with less evidence for strength or power. EFSA considers a single dose of up to 200 mg safe for healthy adults when taken less than two hours before intense exercise in normal conditions. You do not need the sugar or the extra ingredients for that effect: a coffee does the same job. If you train in the evening, remember that caffeine can still be active at bedtime. For food ideas, see what to eat before a workout.
How can you cut back if you drink them every day?
- Add up your caffeine first. Count every can, coffee, tea and cola for a few days to see your real total.
- Cut gradually. Dropping a large habit overnight can bring headaches and tiredness; reducing by one drink every few days is gentler.
- Swap the regular can for sugar-free as a first step, then replace some cans with coffee, tea or sparkling water.
- Set a cut-off time, for example no caffeine in the six hours before bed.
Is it risky to mix energy drinks with alcohol?
NCCIH highlights this combination as a particular concern. Caffeine can mask how drunk you feel without improving coordination or reaction time, so people may drink more and take more risks. Data cited by NCCIH show that young drinkers aged 15 to 23 who mix the two are four times more likely to binge drink at high intensity. Alcohol also brings its own calories: 7 kcal per gram.
What are better options when you need a lift?
- Coffee or tea without sugar. Similar caffeine, almost no calories. See coffee and tea calories for what milk and syrups add.
- Water first. Mild dehydration can feel like tiredness.
- A snack with protein and fibre. Yogurt with fruit or a handful of nuts gives steadier energy than a sugar spike.
- A short walk or some daylight. Moving for a few minutes often helps afternoon fatigue.
- If you do drink one, choose a smaller or sugar-free can, count it towards your daily caffeine and keep it well away from bedtime.
When you log a drink in Sporty, scanning the barcode records the label values for that exact can, which is more accurate than a generic entry because brands differ so much.
This article is general information, not medical advice. Children, teenagers, pregnant or breastfeeding women and people with heart problems, high blood pressure, anxiety or sleep problems should be especially careful with caffeine and talk to a doctor if unsure.
Frequently asked questions
How many calories are in an energy drink?
A regular 16 oz (473 ml) energy drink with 54–62 g of sugar has about 215–250 kcal from sugar. Sugar-free versions are close to zero calories but contain the same caffeine.
How many energy drinks a day is safe?
It depends on the caffeine per can. EFSA considers up to 400 mg of caffeine a day from all sources safe for healthy adults, so count coffee, tea and cola too. Children, teenagers and pregnant women need much lower limits.
Are sugar-free energy drinks better for weight loss?
They remove most of the calories, which helps a calorie deficit. They still contain caffeine, so sleep and daily caffeine limits still apply.
Is coffee healthier than an energy drink?
Plain coffee or tea gives a similar caffeine lift with almost no calories and no added sugar, which makes it the simpler choice for most adults.
Was this article helpful?
No ratings yet — be the first.
Tap a star to rate it — your rating helps us improve and helps other readers.
Sources
This article is general information, not medical advice. If you have a health condition, are pregnant or under 18, talk to a doctor or registered dietitian before changing your diet.