The Use of All-You-Can-Drink System, Nomihodai, Is Associated with the Increased Alcohol Consumption among College Students: A Cross-Sectional Study in Japan.

Excessive drinking by college students is a major public health problem in Japan. However, data on heavy episodic drinking (HED) and nomihodai, a several-hour all-you-can-drink system, are scarce. We surveyed the drinking behavior of undergraduate and graduate students at 35 colleges, and examined the association between HED and use of nomihodai. The study used a cross-sectional design conducted by a self-administered questionnaire. From December 2016 to March 2017, we sampled undergraduate and graduate students aged 20 or older at 35 colleges in the Kanto area, including Tokyo. The following items were measured: 1) frequency of drinking; 2) frequency of binge drinking in the past year; 3) nomihodai use; 4) the number of drinks consumed when using or not using nomihodai; and 5) sex and age for demographic data. Paired t-test was used to compare means between use and non-use state of nomihodai. The Fisher's exact test was used to evaluate the significance of the distribution difference between the two types of states. A total of 511 subjects completed the questionnaire, including 274 men and 237 women. The amount of drinking was increased 1.8-fold (85.9 +/- 49.7 g vs. 48.2 +/- 29.5 g) among men and 1.7-fold (63.7 +/- 39.3 g vs. 36.5 +/- 26.7 g) among women during nomihodai use, comapred with non-use states. Among them, 109 (39.8%) men and 71 (30.3%) women reported HED only at nomihodai states. These data suggest that the use of nomihodai system may lead to excessive drinking among college students.