Lifestyle behaviours of children and adolescents during the first two waves of the COVID-19 pandemic in Switzerland and their relation to well-being: a population-based study
Authors: Peralta Gabriela P. , Camerini Anne-Linda , Haile Sarah R. , Kahlert Christian R. , Lorthe Elsa , Marciano Laura , Nussbaumer Andres , Radtke Thomas , Ulyte Agne , Puhan Milo A. , Kriemler Susi 
Published: December 2021

SUMMARYBackgroundPrevious studies assessing the impact of the COVID-19 pandemic on children’s and adolescent’s lifestyle focused mainly on the first wave in early 2020. We aimed to describe changes in adherence to recommendations for physical activity (PA), screen time (ST), and sleep duration over the first two waves of the pandemic (March-May 2020 and October 2020-January 2021) in Switzerland, and to assess the associations of these lifestyle behaviours with life satisfaction and overall health, as indicators of well-being.MethodsWe included 3168 participants aged 5 to 18 years from four Swiss cantons. Participants or their parents completed repeated questionnaires and reported on their (child’s) PA, ST, sleep, life satisfaction, and overall health. We analysed lifestyle behaviours in terms of adherence to international recommendations. We used linear and logistic regression models to assess the associations of number of recommendations met and adherence patterns with well-being indicators.FindingsCompared to the pre-pandemic period, the percentage of participants meeting the recommendations for PA and ST decreased strikingly during March-May 2020, while there was a slight increase in those meeting recommendations for sleep. During October 2020-January 2021, the percentage of compliant children for PA and ST increased but remained lower than before the pandemic. Participants meeting all three recommendations were more likely to report excellent health (OR: 1·87 [1·15-3·08]) and a higher life satisfaction score (β: 0·59 [0·30-0·88]) than participants not meeting any recommendation. Adherence to recommendations for PA and sleep, PA and ST, and sleep and ST was similarly associated with both well-being indicators.InterpretationWe show a substantial impact of the COVID-19 pandemic on children’s and adolescents’ lifestyle behaviours with a partial recovery over time, and an association between lifestyle and well-being. Public health policies to promote children’s and adolescents’ well-being should target PA, ST, and sleep simultaneously.FundingCorona Immunitas.RESEARCH IN CONTEXTEvidence before the studyWe searched PubMed for studies assessing the effects of the COVID-19 pandemic on children’s and adolescents’ lifestyle behaviours, published up to September 6, 2021, with no language restrictions. Of the studies found, nearly all compared lifestyle behaviours before and during the strict confinement in the first wave of the pandemic, and very few studies extended their assessment beyond June 2020. The only longitudinal study assessing lifestyle changes up to 2021 included a sample of nineteen boys. Some studies assessed the association between lifestyle behaviours and well-being after the outbreak of the pandemic, but all used a single-behaviour approach (i.e., evaluated only one lifestyle behaviour) and no study considered the combined contribution of physical activity (PA), screen time (ST), and sleep. In addition, most studies were cross-sectional and did not consider pre-pandemic lifestyle behaviours.Added value of this studyThis is the first study assessing changes in adherence to international recommendations regarding PA, ST, and sleep duration in children and adolescents during the first two waves of the COVID-19 pandemic and the joint associations of these lifestyle behaviours with well-being. We used data from 3168 children and adolescents from four different Swiss cantons. We included measurements of PA, ST, and sleep before the pandemic, during the first wave between March and May 2020, and during the second wave between October 2020 and January 2021. We also assessed life satisfaction and overall health as indicators of well-being, between January and April 2021. We showed that, compared to the pre-pandemic period, the proportion of children and adolescents following the recommendations for PA and ST decreased during the first wave (lockdown period), while there was a slight increase in those meeting recommendations for sleep. During the second wave, the prevalence of compliant children and adolescents for PA and ST recovered but remained below pre-pandemic levels. Furthermore, we found an association between the number of recommendations met for lifestyle behaviours during the second wave and well-being assessed between January and April 2021. In contrast, there was no such association for the periods before the pandemic or during the lockdown. Participants following the recommendations for all three lifestyle behaviours or for combinations of two of them in the second wave were more likely to report excellent health and had a higher life satisfaction score, than those not meeting any recommendation.Implications of all the available evidenceOur findings demonstrate that the COVID-19 pandemic has had a strong negative effect on children’s and adolescents’ lifestyle behaviours, but some recovery has taken place within the first year since the outbreak. Policymakers should imperatively consider the balance of disease prevention and promotion of a healthy lifestyle when (re-)activating restrictive measures. Given the already high prevalence of children and adolescents not meeting lifestyle recommendations in the pre-pandemic period, our findings highlight the urgent need for public health policies aiming to avoid permanent negative changes on children’s and adolescents’ lifestyle and to mitigate the health risks associated with adverse changes during the pandemic. In addition, our study indicates that lifestyle is an important predictor of children’s and adolescents’ well-being, and it further suggests that future public health strategies aiming to promote well-being should target sufficient time for PA and sleep as well as reduce ST.