Mixing alcohol with energy drink (AMED) and total alcohol consumption: a systematic review and meta-analysis

It has been suggested that consuming alcohol mixed with energy drink (AMED) may increase total alcohol consumption. Aims of this systematic review and meta-analysis were (i) to compare alcohol consumption of AMED consumers with alcohol only (AO) consumers (between-group comparisons), and (ii) to examine if alcohol consumption of AMED consumers differs on AMED and AO occasions (within-subject comparisons). A literature search identified fourteen studies. Meta-analyses of between-group comparisons of N = 5212 AMED consumers and N = 12,568 AO consumers revealed that on a typical single drinking episode AMED consumers drink significantly more alcohol than AO consumers (p = 0.0001, ES = 0.536, 95%CI: 0.349 to 0.724). Meta-analyses of within-subject comparisons among N = 2871 AMED consumers revealed no significant difference in overall alcohol consumption on a typical drinking episode between AMED and AO occasions (p = 0.465, ES = -0.052, 95%CI: -0.192 to 0.088). In conclusion, between-group comparisons suggest that heavy alcohol consumption is one of the several phenotypical differences between AMED and AO consumers. Within-subject comparisons revealed, however, that AMED consumption does not increase the total amount of alcohol consumed on a single drinking episode.