This study aims to identify opportunities and barriers in developing and implementing Food Shopping Support Systems (FSSS) for healthier and more sustainable choices, given the growing consumer demand and persistent societal problems related to food. The study examined the social and technical value of FSSS in an early development stage through one-on-one expert interviews (n = 20) and consumer focus groups (4 groups, n = 19). Experts were employed in the fields of behavioral sciences, digital marketing, decision aids, software development, persuasive technologies, and public health and sustainability. Consumer participants were used to shopping online. Through a card sorting task followed by semi-structured interview questions, responses were elicited. Participants were presented with 17 cards in 5 rounds, each addressing a different topic related to decision support. Results show that support is perceived useful, particularly when suggestions are personalized, transparent, and justified (using labelling or informative text). Opportunities for uptake were presenting suggestions early in the shopping trip in a visible but non-disruptive manner, allowing autonomy to choose the type of guidance (e.g., show sustainable but not healthier suggestions) and to (not) provide personal data, and educating consumers. Negative attitudes were associated with support being disruptive or steering, being of low credibility, and unclarity about what is healthy or sustainable. Consumer participants expressed concerns about too generic suggestions in relation to health and lack of knowledge about labelling. They emphasized that excessive support and required effort, such as repeatedly providing data, can be burdensome. Experts also worried about limited consumer interest and not having the required data to provide support. Results from this study reveal the potential for successful digital interventions to encourage healthier and more sustainable choices and what this means for further development.