AIMS/HYPOTHESIS: Metabolic effects of intermittent unhealthy lifestyle in young adults are poorly studied. We investigated the gluco-metabolic and hepatic effects of participation in Roskilde Festival (one week of binge drinking and junk food consumption) in young, healthy males.METHODS: Fourteen festival participants (FP) were studied before, during and after one week's participation in Roskilde Festival. Fourteen matched controls (CTRL) who did not participate in Roskilde Festival or change their lifestyle in other ways were investigated along a similar timeline.RESULTS: The FP group consumed more alcohol compared to their standard living conditions (2.0±3.9 vs 16.3±8.3 units/day, pCONCLUSIONS/INTERPRETATION: Participation in Roskilde Festival did not affect oral glucose tolerance, but was associated with a reduction in insulin sensitivity, increases in glucagon, FGF21, GDF15 and AST and lead to increased liver stiffness and, in 29% of the participants, ultrasound-detectable hepatic steatosis.