The first separately printed treatise on diet was written by the Egyptian-Jewish physician and philosopher Isaac Judaeus who lived from about 832 to 932 CE. He was also known as Isaac Israeli ben Solomon and Abu Ya'qub Ishaq Sulayman al-Israili. The Latin edition was a translation made from the Arabic, circa 1070, by Constantine the African (Constantinus Africanus). De particularibus diaetis was a portion of " 'Kitab al-Adwiyah al-Mufradah wa'l-Aghdhiyah,' a work in four sections on remedies and aliments. The first section, consisting of twenty chapters, was translated into Latin by Constantine [the African] under the title 'Diætæ Universales,' and into Hebrew by an anonymous translator under the title 'Ṭib'e ha-Mezonot.' The other three parts of the work are entitled in the Latin translation 'Diætæ Particulares'; and it seems that a Hebrew translation, entitled 'Sefer ha-Mis'adim' or 'Sefer ha-Ma'akalim,' was made from the Latin" (Wikipedia article on Isaac Israeli ben Solomon, accessed 06-08-2009). A more complete printed edition of the text appeared in Basel in 1570. Campbell, Arabic Medicine and its Influence on the Middle Ages I (1926) 73. ISTC no. ii00176000. Digital facsimile from Regensburger Reichsstädtische Bibliothek Online (RRBO) at this link.

Constantine was a Muslim from North Africa who converted to Christianity. His writings were first published with those of Isaac Judaeus in the above edition which includes many separate texts. Many of the writings of Constantine were translations into Latin of Greek, Arabic and Jewish writers. Through his translations he placed Muslim thought and culture at the disposal of European medicine from the 12th to 17th centuries. For a time he taught at the School of Salerno. Digital facsimile of the Lyon 1515 edition from the Herzog August Bibliothek at this link. Digital facsimile of the Basel, 1536 edition of Constantine's works from Google Books at this link.