Obesity is now recognized by many medical associations as a pathological condition. In this article, I first focus on the construction of nosological entities before discussing the stages that led to the medicalization of obesity in the last century. I then examine the main approaches in the philosophy of medicine to determine whether they offer arguments in favor of, or against, the thesis that obesity is a disease. I argue that the naturalistic approach, which is more sensitive to biomedical data, fails to specify in what way obesity would be a disease ; and that if the normativist approach succeeds better, it is at the cost of a permissiveness from which we can fear the excesses. Nevertheless, the latter makes it possible to highlight the social and biological part of pathologies in their identification as pathologies. My conclusion will be similar to that of Hofmann : the reasons put forward for arguing that obesity is a disease in the proper sense are mainly pragmatic in nature.