Aim: The ways by which food is produced, distributed, and consumed have an impact on the approach to food sustainability. It is important to involve all system actors, including consumers toward more sustainable systems. There is a lack of work on transitions in food towards sustainability at territorial level. The aims of this study are to better understand consumers definition of sustainable food, to explore perceptions and expectations of food at workplace and to identify important criteria in terms of a sustainable food offer. Method: Two focus goups were performed with French people (n=20). Participants, were recruited on the basis of eating at canteen at least once a week. Focus groups were conducted in Plateau de Saclay, Ile-de-France. Discussion was conducted in 4 steps : i) introduction, ii) perception of sustainable food at home, iii) perception of sustainable food at collective catering, iv) indicators of food sustainability. Results: For participants sustainable and healthy eating involves a balanced meal including fruit and vegetables, pulses, cereals, less processed foods as well as less environmental impact, eating less red meat, local, diminishing food waste and food packaging and fair remuneration to all the actor of the food chain. The main difficulties encountered in order to consume more sustainable were: the cost, accessibility and lack of time allowed to food preparation. Regarding the choice of meals in collective catering, participants highlighted that offer is balanced, a little weak for vegetarians. They would like to have more information about the origin of the products. For participants, criteria for having a sustainable food is eating food coming from short circuits, seasonal, few pesticides, less meat. Participants mentioned a lack of information about the origin of products and that multiple food labels leads to confusion. Conclusion: Consumers perceptions of food sustainability involve classical pillars (health, environmental, economical and social dimensions). Regarding food sustainability, some difficulties were highlighted by participants such as time and cost issues. Collective catering might improve communication and collaboration with consumers (e.g. about the origin of the products, labels, agricultural practices). Observational studies will allow to identify specific consumers leverages to attain sustainability.