BACKGROUND: Changes in Swedish university students' lifestyle behaviors during the COVID-19 pandemic are unknown. This study aimed to assess physical activity, sitting time, meal frequency and risk substance use (alcohol, tobacco, and illicit use of drugs) in Swedish university students before and during the first six months of the COVID-19 pandemic, for all and stratified by age and sex.

METHODS: Data were obtained from the Sustainable University Life cohort study in which web-based surveys were sent to university students repeatedly for one year. Baseline assessment (before the pandemic) was between August 2019-March 2020, follow-up 1 (FU1) between March-June 2020, and follow-up 2 (FU2) between June-September 2020. Participants reported weekly minutes of physical activity, daily sitting hours, meal frequency by weekly intake of different meals, and motivation for eating irregularly, if so. Also, harmful use of alcohol, tobacco and illicit drugs was assessed. Population means and differences with 95% confidence intervals (95% CI) in lifestyle behaviors between time points were calculated with Generalized Estimating Equations.

RESULTS: 1877 students (73% women, mean age 26.5 years) answered the baseline survey. Weekly exercise decreased by -5.7 min (95% CI: -10.0, -1.5) and -7.7 min (95% CI: -12.6, -2.8) between baseline and FU1 and FU2, respectively. Weekly daily activities increased by 5.6 min (95% CI: 0.3, 11.7) and 14.2 min (95% CI: 7.9, 20.5) between baseline and FU1 and FU2. Daily sitting time decreased by -1.4 h (95% CI: -1.7, -1.2) between baseline and FU2. Breakfast intake increased by 0.2 days per week (95% CI: 0.1, 0.3) between baseline and FU2. Lunch intake decreased by -0.2 days per week (95% CI: -0.2, -0.1) between baseline and FU1 and by -0.2 days per week (95% CI: -0.3, -0.0) between baseline and FU2. Dinner intake decreased by -0.1 days per week (95% CI: -0.2, -0.0) between baseline and both FU1 and FU2. Only minor differences in risk substance use were observed. Similar changes were observed in analyses stratified by age and sex.

CONCLUSIONS: Lifestyle behaviors in Swedish university students slightly improved during the first six months of the COVID-19 pandemic compared to before.

TRIAL REGISTRATION: ClinicalTrials.gov, NCT04465435 . 10/07/2020.