[Health and dietetics in medieval preventive medicine: the health regimen of Peter of Spain (thirteenth century)].

This text is an analysis of a preventive medical work, Liber de conservanda sanitate, composed in the thirteenth century by the Portuguese physician and doctor, Peter of Spain (?1210-1277). His work enables us to look at the conceptions of health and hygiene and understand the social role of university physicians in medieval preventive medicine. The work constantly displays the notion of the balance in corporal health between internal elements, or natural things (complexion, for example), and external ones, or non-natural things (air, sleep, exercise, food, baths, passions of the soul).