Eating healthier at work can substantially promote health and well-being among knowledge workers. However, little has been investigated on designing digital tools and interventions specialized in improving workday eating routines. This paper presents a user-centered contextual inquiry based on mixed-methods with an online questionnaire and a semi-structured interview. This study aimed to understand knowledge workers’ eating experiences and identify design opportunities and application strategies of digital tools to improve current practices. The questionnaire feedback from 54 Dutch knowledge workers revealed that their concerns over productivity, health and nutrition, energy support, and well-being could be decisive in shaping their eating routines at work. Furthermore, the results of 12 interview sessions suggested a set of expected digital features to encourage healthy eating at work, including health knowledge access, goal setting and self-tracking, technology-assisted health programs, and social support. Additionally, our findings also indicated that these digital features should be integrated into the office setting to offer personalized feedback and contextualized health interventions. Based on these findings, we derive design opportunities for workplace digital tools to promote healthy eating and discuss their potential contributions and future work to improved office vitality.