Obesity and substance use : does higher BMI increase risk?

Emerging adulthood is a time of significant change where behaviors are adopted that can have significant long term effects on health. The most dramatic increases in weight are occurring among emerging adults, especially those with some college education. Emerging adults are also at an increased risk for substance use and abuse. The current study examined the relationship between BMI and substance use among college students. Participants included 703 undergraduate students at a large public U.S. university (M age=20.6, 58.7% Non-Hispanic White, 59.8% female). Students completed an online survey with items on substance use behaviors such as smoking, alcohol use, marijuana use, and binge drinking. Tobacco, alcohol, marijuana use, and binge drinking were assessed with one question asking students how many days over the past month they had used the specific substance (range 0-30 days). Binge drinking was assessed using one question: “Over the last two weeks, how many times have you had five or more drinks of alcohol at a sitting?” Responses ranged from 0 to 10 or more times. Substance use behaviors were coded to no use/any use in the past month. Body mass index was calculated through the student’s self reported height and weight. BMI was significantly related to past month tobacco use with an odds ratio of 1.06 (95% CI: 1.01-1.12). Specifically, with every one unit increase in BMI, the odds of past month tobacco use increased by 6%. However, BMI was not significantly associated with past month alcohol use, marijuana use, or binge drinking (p>.05). As BMI increases, college students’ odds of using tobacco increase. This finding is particularly problematic given that weight gain is common among undergraduate students and cigarette use has been cited as a common weight management practice among this group as well. Future research should consider the role of BMI as a factor in decreasing tobacco use.