Teachers in Slovenia have been noticing the increased consumption of energy drinks among pupils. Therefore, the purpose of this study was to investigate habits that contribute to the frequency of energy drink consumption. 36 teens participated in the study: elementary school pupils (6th and 8th grades), general upper secondary school pupils, and secondary technical school pupils (1st and 3rd year). In the course of the study 6 group interviews were held to help investigate young people's habits and their reasons for energy drink purchase and consumption. Moreover, we investigated the influence of age on the consumption and knowledge about energy drink ingredients, as well as their influence on the body. Interview analysis showed that energy drink consumers are predominantly secondary school pupils. Their choice most frequently depends on the price, their taste, or the brand. What influences elementary school pupils' purchasing decisions are price, packaging, and advertisements, while secondary school pupils choose their drinks according to the lack of energy and how tired they feel. The predominant factors preventing energy drink consumption are health problems among family members and friends. Secondary school pupils know more about energy drink ingredients than elementary school pupils. On the basis of these findings, we will design a survey questionnaire for Slovenian teenagers and teachers, didactic material, and suggestions for improving educational programmes.