Category Archives: caffeine

Energy drinks, caffeine and young adults

The puzzle:

There has been considerable recent interest in the impact of energy drinks on teenagers and young adults (BBC News 2018a, 2018b, 2019), and there is a statutory requirement to provide a high caffeine warning on drinks containing more than 150 mg/L of caffeine. The overt purpose of adding caffeine to soft drinks is as a “flavouring agent” as it possesses a strong bitter taste. There is, however, evidence that caffeine at concentrations found in colas and within a complex matrix cannot be detected by a trained sensory panel wich has led some to hypothesise that caffeine was added for its mildly addictive properties rather than its taste. The impact of caffeine at higher concentrations such as those typically found in energy drinks remained unclear. Additionally, although we know that labelling and marketing information can generate strong expectations and impact on the experience of consumption and liking of a product, there was little information on whether information relating to caffeine presence influences healthiness perception and intended use in young adults.

The research:

Over 2017-18 and 2018-19, two learning sets of final undergraduate students in Food and Nutrition at Sheffield Hallam University worked under the supervision of Dr Cecile Morris to better understand the role of caffeine in model energy drinks and its impact on liking and perception. The information collected formed the basis for an article co-authored by one of the students, Jessica Elgar, in the academic journal LWT Food Science and Technology.  In brief, a consumer panel of 107 young adults (18-26 years of age) was recruited to assess one caffeinated and one caffeine-free model drink in both a blind condition (i.e. participants had no information about the presence of caffeine) and an informed condition (i.e. participants had information about whether the drink contained caffeine or not). Habitual caffeine intake was also measured.

The findings:

Energy drinks contributed only 5.2% to the participants’ overall caffeine intake, behind coffee and tea, and their consumption pattern appeared to be irregular rather than habitual. This broadly relates to what has been observed elsewhere and suggests that energy drinks may not be problematic with respect to overall caffeine intake. Caffeine in concentrations found in energy drinks could be detected by the participants. Both the presence of caffeine and information that caffeine was present in the drink had small, but significant detrimental effects on overall liking and liking of the bitterness level. This may explain why energy drinks often contain a lot of sugar as the sweetness masks off the bitter taste of caffeine. Healthiness perception also decreased when participants were informed that the drink contained caffeine.

A potentially bigger issue emerged from the findings with regard to how young adults planned to consume the model energy drinks: the most popular intended use for the caffeinated model energy drink, both in blind and informed conditions, was as a mixer with alcohol. This however is unlikely to be attributable specifically to the presence of caffeine in the drink as the most popular intended use for the caffeine-free model drink was also as a mixer with alcohol. Similarly, no significant difference was observed between intended purposes relating to the energy boosting properties of energy drinks.

These results and the enduring popularity of energy drinks suggest that there is more at play than taste, healthiness perception or their even energy boosting properties. Some have hypothesized that their acceptance may be linked to the positive feelings experienced when their consumption alleviates mild caffeine withdrawal symptoms. Unpicking this may prove practically challenging but would be particularly useful, as would exploring the views of younger teenagers.

About the author:

Dr Cecile Morris ( is Interim Head of the Department of Service Sector Management, Sheffield Business School of Sheffield Hallam University. Her research focuses on sensory science, food perceptions, consumer attitudes and behaviours, health and food science.

Cecile and Jessica’s article, ‘Impact of caffeine and information relating to caffeine on young adults’ liking, healthiness perception and intended use of model energy drinks’ appears in the October 2020 issue of the Journal LWT: Food Science Technology.

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