Use of video-based telehealth services using a mobile app for workers in underserved areas during the COVID-19 pandemic: A prospective observational study

•The COVID-19 pandemic triggered a change in the structure of healthcare services.•Effects of a video-based telehealth app on workers’ health/lifestyle were tested.•Except for HDL cholesterol, metabolic risk factors showed a significant improvement.•Dietary scores showed a significant improvement, but physical activity did not.•The mobile app can help workers access healthcare during the COVID-19 pandemic.