The aim of this study is to provide an overview of research into school curricula regarding body image and attitudes toward obesity and its relationship with physical activity to show the different trends and propose future considerations and pedagogical implications in this area. These implications are formulated through a teaching unit containing seven sessions on body image, self-esteem and values, diet, physical activity, media, fashion trends, and emotions. This unit is developed for the fourth year of secondary. The proposal implemented in the school would be addressed through a socio-critical model of health-oriented physical education (PE). Prevention is the ideal treatment for obesity and schools are appropriate contexts to inform and educate about healthy habits such as physical activity, sport and eating, as well as to promote a positive body image (BI) and eradicate, as far as possible, the negative attitudes toward obesity.