The Classification of Foods in Physician Shirvani’s Nutrition Book Ya‘kūbiyye

Abstract

This article examines the nutritional principles and food classification system presented in the Arabic work Ya‘kūbiyye by the 15th-century Ottoman physician Muhammed bin Mahmud Shirvani. The work is among the earliest examples of Ottoman medical literature that integrates both theoretical and practical aspects of nutrition. Shirvani presents a multi-layered approach, classifying foods not only by their temperament but also by their effects on the body, their digestibility, nutritional value, and the type of chyme— the semi-liquid mass formed in the stomach after food is ground and partially digested—into which they are transformed. The work, which consists of twenty-three chapters, examines in detail various aspects of foods such as their being sweet or gallic, their benefits or harms to the stomach, waste production, potential for bloating, and blockage. Shirvani’s classification method reflects not only the medical knowledge of his time but also serves as a guide for public health. The plain language and didactic style of the work indicate that it was intended for both physicians and the public. Furthermore, the text emphasizes that each individual should be nourished according to their temperament, and the foundations of the concept of personalized diet in classical medicine are shed light on. The importance of consuming foods in proper combinations, their appropriate processing and preparation, and their suitability to one's temperament is underscored. Ya‘kūbiyye stands as a valuable source in terms of historical context, theoretical insight, and practical application, representing one of the earliest systematic approaches to preventive medicine and dietetics in the Ottoman medical tradition. In this respect, it not only contributes to historical medical literature but also offers inspiration for contemporary studies in nutrition and dietetics.