Identifying determinants of body composition in undergraduate students: a systematic review and protocol for a prospective observational study

Abstract

Young adulthood is an important period in the development of obesity. Undergraduate students are particularly at-risk since they gain more weight than those not attending university. As students transition from high school to university, they often adopt unhealthy lifestyle behaviours which are thought to lead to weight gain. On average, students gain three to five pounds (1.4-2.3 kg) during their first year of undergraduate education. However, less is known about how body composition changes throughout the four-year course of undergraduate education and what causes these changes. We thus conducted a systematic review to synthesize a comprehensive list of factors associated with obesity traits (e.g. body mass index, body fat percentage, muscle mass) in undergraduate students. Two hundred thirty-eight studies were included (175 cross-sectional, 49 cohort, 11 interventional, 3 qualitative). We identified age, sex, ethnicity, socioeconomic status, religion, diet, eating habits, physical activity, sedentary activity, sleep, stress, university campus life, alcohol use, smoking, psychiatric disorders, body image, eating attitude, eating regulation, personality, and social/cultural influences as factors which are associated with obesity traits. These factors guided the design of the Genetic and EnviroNmental Effects on weight in University Students (GENEiUS) study, a prospective observational study which investigates the genetic and environmental determinants of body composition in undergraduate students over four years. The GENEiUS study will recruit 2500 multiethnic first- year undergraduates aged 17–25 years and will follow them every six months for four years. Primary outcomes are body mass index, waist circumference, waist-to-hip ratio, body fat mass and body fat percentage. This study will help design obesity prevention programs in universities.