[The fight against obesity by physical activity and the foundations of an expert consensus]

From a sociological point of view, this article investigates the conflicting arguments about physical activity (type of activity and content of recommendations) between experts in the fight against obesity. We studied a variety of different media: press articles, reports, books, popular articles, interviews, ethnographic notes. These data were analysed by Prospero software followed by R software and the TraMineR package. The article primarily shows that a general consensus has been reached that physical activity is an important factor in fighting obesity in contrast with the divided debate about nutrition amongst experts. The proposed French nutrition policy is marked by nonspecific recommendations. However, this apparent consensus fails to define the various types of physical activity and remains confusing about the nature of the expected beneficial effects. More detailed analysis of the debates and concepts reveals divergent points of view. We distinguished three main issues related to physical activity as a health recommendation and demonstrated that the emerging controversies concerning nutrition have not been resolved. These concepts tend to recur in the debates about physical activity because they are based on the fundamental tension between a biological and a more psychosociological vision of health and physical education. In conclusion, this article examines the construction of indicators linking physical activity to health from the points of view of various experts. .