Objective:To examine whether the incidence of health problems increases during the COVID-19 pandemic.Methods:Using the health examination data (April 2018-March 2021) of Japanese workers aged 15 to 64 years, the 1-year incidence of five health problems (overweight, hypertension, hypercholesterolemia, hyperglycemia, and liver damage) and four unhealthy habits (snacking, heavy drinking, physical inactivity, and sleep deprivation) were compared before and during the COVID-19 pandemic.Results:The 1-year incidence of overweight, hypertension, hyperglycemia, and liver damage increased by 15% to 65% during the COVID-19 pandemic. Increased weight gain, related to decrease physical activity during the COVID-19 pandemic, was significantly associated with increased incidence of health problems.Conclusions:The COVID-19 pandemic have deteriorated workers’ health even without the COVID-19 infection. Lifestyle interventions should be promptly started particularly targeting workers with gained weight to avoid more serious consequences.