Body mass index in young men in Switzerland after the national shutdowns during the COVID-19 pandemic: results from a cross-sectional monitoring study at the population level since 2010

Abstract

Background Owing to the COVID-19 pandemic, the Swiss goverment imposed a shutdown twice, which may have changed diet and physical activity. Regarding the question of weight change during the pandemic, little information based on measured weight data is available. We aimed to investigate whether the body mass indices (BMIs) of young Swiss men after the two shutdowns in spring and fall 2020 differed from those of young men examined before the shutdowns. Methods We analysed young Swiss men’s BMIs taken during mandatory recruitment for the Swiss Armed Forces at the cross-sectional (not individual longitudinal) monitoring level and across weeks of conscription between January 2010 and July 2021 (n = 373,016). These data allow for continuous health monitoring of young men at almost the population level (coverage, >90%). For statistical modelling, we used the generalised additive model (GAM) framework. Results We showed that the BMIs of the conscripts examined in the 15 weeks after the two shutdowns in spring and autumn 2020 were not or only slightly different from their baseline values. Sensitivity analyses revealed that this conclusion also holds if the BMI distribution or prevalence of excess weight is assessed. The GAM further showed the significant effects of individual and area-based measures of socioeconomic position and age on BMI. Conclusion Our results suggest that lifestyle changes during the pandemic in young men might have been too modest to be reflected in body weight. However, longitudinal data and/or data on women, children, or the elderly may lead to different conclusions.

Trends of physical fitness related to weight status: An analysis including over 412,000 Swiss young male conscripts from 2007 to 2022

“…The decline in physical fitness observed among Swiss male conscripts with excess weight over the conscription years cannot be attributed to higher BMI, as it remained stable in this population ( Meili et al, 2022 ). Moreover, physical activity levels have been reported to increase in the past decade in the Swiss population ( Office and Survey, 2017 ).…”

“…Instead, it is possible that modern lifestyle factors, such as sedentary behaviour (i.e., mainly time spent sitting), and unhealthy dietary habits contribute to the detrimental impact of excess weight on physical fitness. In particular, the influence of COVID pandemic seems to be excluded as (i) the trend was continuous since 2007, and (ii) the lifestyle changes during the pandemic in this population seems to have been modest ( Meili et al, 2022 ). Also, the reason why the musculoskeletal component appears more prone to worsen over time is not fully understood but might be explained by the non-negligeable genetic influence on cardiorespiratory fitness ( Zadro et al, 2017 ).…”