The development of a global food system able to guarantee everyone a balanced food intake requires health professionals an awareness and a commitment to education increasingly complex. FAO strongly recommends the development of a code of conduct for sustainable diets. Sustainable diets are those diets with low environmental impacts which contribute to food and nutrition security and to healthy life for present and future generations. We wanted to examine, through a specific questionnaire, the opinions of scientific italian opinion leaders on this topic. The comments received confirm the variability of the concept of sustainability among those who participated in our survey. In relation to the consumption of certain foods we detect the potential conflict between "healthy" and "sustainable". The nutritional need of increasing the consumption of healthy foods is widely shared, but more than a doubt emerges about the sustainability of these solution. Our survey shows the absolute necessity of shared documents in this regard (recommendations and/or guidelines) and of a thorough implementation of such documents among opinion makers.