Prevalence and demographic, substance use, and mental health correlates of fasting among US college students

Plain english summary Fasting has recently garnered public attention given its purported benefits, including weight loss and improved physical functioning. To date, little research has been conducted to determine the prevalence of this behavior among college students, as well as what demographic characteristics, substance use behaviors, and mental health symptoms are associated with this behavior. Results from a sample of over 8000 college students from four survey years of the Healthy Minds Study show that fasting is common among college men and women and has increased in prevalence from 2016 to 2020. Fasting is associated with indicators of poor mental health including depression, anxiety, eating disorder symptoms, suicidal ideation, and non-suicidal self-injury (e.g., cutting, burning), among both college men and women. Fasting is associated with substance use behaviors, including marijuana use and other illicit drug use (e.g., cocaine, ecstasy), among college women. These results highlight the adverse correlates of this common weight loss and compensatory behavior among college students. Background Fasting is an unhealthy behavior that has been frequently used as part of weight loss attempts. To date, little research has been conducted to determine the prevalence and substance use and mental health correlates of fasting among college students. Therefore, the aim of this study was to estimate the prevalence and associations between any (>= 1 time) and regular (>= 13 times) occurrences of fasting in the past 4 weeks and substance use and mental health correlates among a large sample of college students from 2016 to 2020. Methods Data from four academic survey years (2016-2020; N = 8255) of the national (USA) Healthy Minds Study were analyzed. Unadjusted prevalence of any and regular fasting by survey year and gender was estimated. Multiple logistic regression analyses were conducted to estimate the associations between any and regular fasting and the demographic (age, body mass index, race/ethnicity, sexual orientation, highest parental education), substance use (cigarette use, marijuana use, other illicit drug use, alcohol use), and mental health (depression, anxiety, eating disorder symptoms, suicidal ideation, non-suicidal self-injury) correlates. Results Any fasting in the past 4 weeks was common among both men (14.77%) and women (18.12%) and significantly increased from 2016 (10.30%) to 2020 (19.81%) only among men. Regular fasting significantly increased among both men and women from 2016 (men: 1.46%; women: 1.79%) to 2020 (men: 3.53%; women: 6.19%). Among men and women, both any and regular fasting in the past 4 weeks were associated with higher odds of all mental health symptoms, including a positive depression, anxiety, and eating disorder screen, suicidal ideation, and non-suicidal self-injury. Among women, but not men, any and regular fasting in the past 4 weeks were associated with higher odds of marijuana use and other illicit drug use (e.g., cocaine, ecstasy). Conclusions The results from this study underscore both the high and increasing prevalence of fasting among a national sample of college students, as well as the substance use and mental health symptoms associated with this behavior. Healthcare professionals both on and off campus should consider screening for fasting behaviors among college students and provide appropriate intervention when needed.