Young adults do not catch up missed drinks when starting later at night-An ecological momentary assessment study.

Drinking heavily in a short period is associated with significant health risks. However, little is known about when heavy drinking occurs during an evening. Recently, research found that individuals increase their drinking pace across the evening, speeding up their drinking. The current study examines whether this speeding up is different depending on when individuals start to drink in the evening. Data on alcohol consumption were collected among 197 young adults in the Netherlands (48.7% female, Mage = 20.8 SD = 1.7) on Thursday, Friday and Saturday evenings for 5 consecutive weeks using questionnaires send to participants' smartphone every hour between 9 p.m.-1 a.m. The final sample consisted of 10,144 questionnaires across 2,781 evenings. On evenings when individuals started to drink early (between 8 and 9 p.m.), more alcohol was consumed in the first drinking hour, yet no increase in acceleration was found compared to evenings when individuals started later. Moreover, starting later resulted in a lower overall evening consumption and less binge-drinking episodes compared to starting earlier. The results indicate that when individuals start drinking later in the evening they do not tend to catch up the "missed" drinks, that is they do not increase their drinking faster when starting later in the evening, and they drink less heavily. Therefore, motivating young adults to postpone their first drink in the evening could help heavy drinking young adults to drink less on weekend evenings. (PsycINFO Database Record (c) 2019 APA, all rights reserved).