The Association Between Sleep and Body Mass Index (BMI) in College Freshmen at Utah State University

Background: Obesity has become a major health problem with increasing prevalence in the United States. Cases of obesity have increased at alarming rates and have almost doubled over the past 40 years. During this same period of time, sleep duration for all age groups has significantly declined. Because sleep duration is a potential mediator of energy metabolism and body weight, it is an important aspect of health. An association between short habitual sleep time and increased body mass index (BMI) has been reported in large population studies for US young adults. Freshmen college students may encounter many environmental and emotional changes that may lead to sleep deprivation. Perhaps, it is sleep deficit within college freshmen that contributes to the phenomena of “The Freshmen 15”, which suggests that college freshmen often gain weight during their first year of college. Objectives: The purpose of this study was to determine the relationship between sleep duration and body mass index (BMI) in a subset of college freshmen at Utah State University during their first academic year. Methods: The “USU Freshmen Health Study” (PI: Heidi Wengreen, PhD, RD) provided all the data needed to study the relationship between sleep duration and BMI. As such, three data collections during the academic year of 2005-2006 were conducted for 186 college freshmen students, ages 18-19, at Utah State University. The data collections occurred during the beginning of fall semester, the end of fall semester, and the end of spring semester. Participants were asked to report an estimate of their average sleep duration for weekdays and weekends during each data collection period. BMI (kg/m2) was calculated based on measured weight and heights, which were measured during each of the three data collection periods. Results: No significant changes in average sleep or average BMI were seen between each data collection for this population. Therefore, the overall mean duration of sleep was 7.33 hours per night while the mean BMI was 23.48.At ...