Studies as part consumption data on energy drinks have shown that older adults consume fewer energy drinks. Younger adults below the age of 40 and young people are more likely to consume this product group.

Recommendations on Consumption

Excessive consumption above the amounts recommended may lead to adverse health effects, in particular in caffeine sensitive individuals. The daily caffeine consumption of an adult person should not exceed 400 mg/day, given experience with people and potential health-related effects. Children, pregnant and breastfeeding women and caffeine sensitive individuals should avoid energy drinks or consume them in minimal quantities.

This is why you should always pay attention to the information on the packaging of energy drinks and energy shots and not exceed the recommended intake quantities. Young people, such as apprentices and students who are considered one of the major consumer groups of energy drinks should generally not drink more than two cans (250 ml) per day. If it is a drink with a caffeine content of more than 32 mg/100 ml – the reference value defined in the Austrian Food Code (see below) – young people should limit their consumption to one can per day.

If larger quantities of energy drinks are consumed combined with intensive athletic activities, this can lead to undesired effects, given the information provided in the literature and by other agencies. The excessive consumption of alcoholic drinks in combination with energy drinks may also cause undesired effects, as this can lead to misjudging the ability to perform or concentrate on a task.

European Food Safety Authority on Safe Caffeine Intake

The European Food Safety Authority EFSA published a scientific expert report on the assessment of the safety of caffeine from all food sources in May 2015. This report considers individual doses of caffeine up to 200 mg and daily rations of up to 400 mg for adults in Europe as harmless.
You can find further results of the expert report under "Evaluation Caffeine".

High caffeine levels and other energy drink ingredients are a repeated reason for concern, given the possible adverse effects they may have on our health. These adverse effects are usually linked with the levels of caffeine -- excessive consumption and consumption in combination with alcoholic beverages. See EU Evaluation on safe levels of caffeine intake under "Evaluation Caffeine".

Approximate Caffeine Levels in Typical Portions 

Those claims showing an alleged positive effect per can, such as "enhances performance", "improves reactions and the ability to concentrate", "improves alertness and vigilance", "stimulates the metabolism", refer to the caffeine content. Such claims are currently subject to scientific evaluations being carried out by EFSA, the European Food Safety Authority.
The name "Energy Drink" alone is no health or nutrition-related information or claim. Beverages differing in their composition only due to lower levels of or an absence of carbohydrates or physiological calories are not considered energy drinks.

The Austrian Food Code refers to the "Code fort the Labelling and Marketing of Energy Drinks" published by the umbrella organisation of the Union of European Soft Drinks Associations (UNESDA) for the labelling and marketing of energy Drinks.

EU Evaluation: safe caffeine intake

Caffeine is harmless for adults in individual doses of up to 200 mg and daily rations of up to 400 mg. These are the summarised results of a scientific expert report published by the European Food Safety Authority (EFSA) on the safety of caffeine. (A 250 ml energy drink can contain about 80 mg caffeine, which corresponds to approximately the average cup of coffee of 150 ml, depending on the amount of coffee, preparation and type of coffee used).

The final evaluation published in May 2015 takes into account caffeine intake from all food sources and includes recommendations for the general public and specific population groups (pregnant women, children, teenagers). Moreover, other questions such as the possible interaction between caffeine and other ingredients of so-called energy drinks, such as alcohol, synephrine and physical activity, were also taken into consideration.

This was the first time that the risks of caffeine intake from all food sources were evaluated at an EU level. The assessment was carried out on the request of many Member States that had expressed their concerns about the health-related impact of caffeine consumption.

The expertise included feedback from Member States, consumer protection associations, industry and other interest groups. The feedback was gathered through public consultations.

Evaluation Results

• Individual doses of caffeine up to 200 mg are harmless for adults (18-65 years), even if they are consumed less than two hours before intensive physical activity. This corresponds to approximately 3 mg/ kg body weight (BW) for a 70 kg adult. 
• A daily intake of caffeine from all food sources up to 400 mg per day (about 5.7 mg / kg BW) is safe for adults, except pregnant women.  
• Adverse interactions between caffeine and other ingredients found in energy drinks – such as taurine and glucuronolactone – or alcohol are unlikely. The short- and long-term effects of the joint consumption of caffeine and synephrine on the cardiovascular system have not been researched sufficiently to date.  
• Caffeine intake of up to 200 mg per day is harmless for the foetus in pregnant women.
• A daily intake of 3 mg / kg BW is considered safe for children (3-10 years) and teenagers (10-18 years). 
• Individual doses of 100 mg consumed shortly before going to bed could extend the time before falling asleep for some adults and shorten their sleep (this corresponds approx. 1.4 mg/kg BW for a 70 kg adult). This is also believed to be the case for children and teenagers at an intake of 1.4 mg/kg BW.

Links for more information

EFSA explains risk assessment: caffeine
Expert report on the safety of caffeine from all food sources: scientific opinion
EFSA press release: Caffeine – EFSA deduces safe intake amounts
Caffeine intake quantities: approximate caffeine information for typical portions (see caffeine content).