In 2008 nearly 185,000 new members were recruited to the U.S. armed forces. Navy and air-force personnel are forbidden to drink alcohol and smoke during their basic training and researchers from RTI international in North Carolina looked at how much people drank before and after starting their basic training. They studied 4,962 young adults, aged between 18 and 25 and found that 43.1% of them had engaged in binge drinking during the month before their basic training, 27.3% of whom could be described as frequent heavy episodic drinkers. This was higher than the average for the rest of the population but the rates after basic training were much lower with 12% being infrequent heavy episodic drinkers and only 9% frequent heavy episodic drinkers. This suggests that although the forces recruit from a pool of heavy drinkers the abstinence involved in basic training reduces this significantly. Over time the rates of binge drinking among the participants climbed again but to nowhere near the levels they had been before.
Bray, Robert M. ... [et al] - Alcohol use after forced abstinence in basic training among United States Navy and Air Force trainees Journal of Studies on Alcohol and Drugs January 2010, 71(1), 15-22