Working from Home and Dietary Changes during the COVID-19 Pandemic: A Longitudinal Study of Health App (CALO Mama) Users

It is plausible that the coronavirus disease 2019 pandemic and related lifestyle changes affected dietary patterns, but existing studies have limitations owing to a cross-sectional design. Using longitudinal data, we examined dietary changes in people due to the pandemic and related lifestyles. We conducted an online survey on lifestyle changes during the pandemic from April 30 to May 8, 2020, among users of a health app called CALO mama provided in Japan. We retrieved and linked the dietary data for 5,929 participants from January 1 to May 13, 2020. Generalized linear mixed models were used to estimate the frequencies of food intake associated with the pandemic and lifestyles. During the governmental declaration of a state of emergency, the frequency of intake of self-made meals (incidence rate ratio [IRR] = 1.05), vegetables (IRR = 1.06), and snacks increased (IRR = 1.04). Similarly, working from home was associated with increased rates of intake of self-made meals (IRR = 1.02), vegetables (IRR = 1.02), fruits (IRR = 1.06), and snacks (IRR = 1.04). In contrast, working hours (self-made meals: IRR = 0.997, fruits: IRR = 0.99, snacks: IRR = 0.99 [per hour]), time spent on childcare (self-made meals: IRR = 0.99, vegetables: IRR = 0.99, fruits: IRR = 0.98 [per hour]), and depressive symptoms (self-made meals: IRR = 0.93, vegetables: IRR = 0.92, fruits: IRR = 0.90) tended to be negatively associated with the frequency of food intake. This study showed that the pandemic affected dietary patterns in various ways. It is important to record and notice such changes and modify them to the recommended balance during a prolonged pandemic to ensure healthy eating habits.