Changes in sleep phase and body weight of mobile health App users during COVID-19 mild lockdown in Japan

Abstract

Objective and method The stay-at-home order during the COVID-19 pandemic has restricted individuals’ social behaviors, and therefore, effected their lifestyle including sleep, diet, and physical activity. Using the cross-sectional study design with a large sample size (N = 30,275) from the mobile health App users in Japan, we show age-dependent lifestyle changes during a nonpunitive “mild lockdown” (from April to May 2020). Results Sleep onset and offset were delayed on work-days but not on free-days with increased sleep duration and decreased social jetlag, and the changes were more evident in the younger population. Although average weight change was close to none because of the users’ characteristic (95% of App users try to lose weight), we investigated an association between lifestyle change and body-weight change. Participants who reported advanced sleep phase during mild lockdown described a weight decrease. In contrast, the delayed sleep phase reported a weight gain. The results were significant after adjustment of confounding factors including physical activity and meal changes. Conclusions Although there is cumulative evidence showing a relationship between late chronotype and obesity, it is still unclear about the potential benefit of the chronotype management to control body weight. Thus, to the best of our knowledge, this is the first study investigating the association between chronotype and weight changes by leveraging a large cohort.

Exploring the effects of COVID-19 restrictions on wellbeing across different styles of lockdown

“…As a result, more people crossed borders of prefectures than during the first declaration, including those commuting between prefectures. In contrast to lockdown in Scotland, restrictions in Japan were requested rather than enforced , with no penalties resulting from violations (e.g., Tahara et al, 2021 ). Therefore, to what extent employers and business owners, and citizens followed the state of emergency depended on populations, economic situations of each institution, and individual beliefs.…”

“…Across a larger sample from the same population, Janssen et al (2020) found that participants’ hours of sleep generally increased during the strictest months of lockdown and decreased again when lockdown began to ease. Sleep duration was reported to have lengthened during mild lockdown in Japan ( Tahara et al, 2021 ).…”

Social Isolation and Sleep: Manifestation During COVID-19 Quarantines

“…Many studies across numerous countries reported a worsening of sleep quality, increasing sleep problems, or increasing problems with insomnia during quarantine conditions (Blume et al, 2020;Peretti-Watel et al, 2020;Pinto et al, 2020;Voitsidis et al, 2020;AlRasheed et al, 2021;Cellini et al, 2021;Conte et al, 2021;Hisler and Twenge, 2021;Hyun et al, 2021;Marelli et al, 2021;Martínez-de-Quel et al, 2021;Robillard et al, 2021). However, some studies found that sleep quality did not worsen across all participants (Benham, 2020;Gao and Scullin, 2020;Kocevska et al, 2020;Tahara et al, 2021). Of these studies, a common trend was that younger people or college students reported less sleep problems during the quarantine (Benham, 2020;Tahara et al, 2021).…”

“…However, some studies found that sleep quality did not worsen across all participants (Benham, 2020;Gao and Scullin, 2020;Kocevska et al, 2020;Tahara et al, 2021). Of these studies, a common trend was that younger people or college students reported less sleep problems during the quarantine (Benham, 2020;Tahara et al, 2021).…”

“…In addition to quality-type measures, many researchers examined changes in sleep patterns during the COVID-19 quarantines. Delays in sleep timing which frequently included a concomitant increase in sleep quantity were commonly found across many countries ( Benham, 2020 ; Blume et al, 2020 ; Sinha et al, 2020 ; Wright et al, 2020 ; Cellini et al, 2021 ; Conte et al, 2021 ; Robillard et al, 2021 ; Tahara et al, 2021 ). The delays in sleep timing included later bedtimes, mid-sleep times, and wake-up times often resulting in less social jetlag (where sleep times differ between workdays and non-workdays).…”