This article analyses effects of health prevention in France, taking nutrition as an example. We show the effects of the individual prevention approach in the accountability process, in particular when it is addressed to an actor whose responsibility remains ambiguous. An ethnography of the implementation of a nutrition education program is realized in the schools of two departments. This study shows the variation in local translations of nutrition recommendations disseminated by the National Nutrition and Health Program. The inculcation of “good practices” of food consumption to kindergarten children is carried out in different school contexts. The central role attributed to the child as an actor and his plural responsibility as a consumer and as a relay of good practices for his family are both declined. The school then relies on the social importance of children’s health to change their behaviour. It also relies on their word to generate a mobilization of the social worlds around them.