It also pains in combat the Vice of gluttony. They fasted compulsorily on many occasions, According to Bertoni. Such custom was always general, from the Antilles and Guyanas to South. Although the reasons may vary, the Guarani fast represented a veritable institution. He fasted and even fasting for various reasons: mystical fasts, medicinal fasts, fasts of education of the will, and other casual. He is considered as a necessary exercise from time to time, and take pride in not being slaves of the eat. Mystical fasts were always common. So fast avare, or karaiva, or page, before attempting one of his evocations and even for the preparation of certain substances or medications.

By the birth of a child, the father also have to fast, strong and happy at the same time. Meticulous cleanliness had been at meals and all matters relating to the preparation of food. Rochefort wrote that you except the days of food in common (fiestas or public meetings), each person had his small table apart. On the table put the most neat of tablecloths, which was a green banana leaf. Always before eating wash your hands with very careful. Very notable contrast with the neglect that many indigenous people of another race (volume III, p. 41) gave a sad example.

Feeding. All Guarani peoples were more or less vegetarian, and some were at all. Even where they ate fish, carnivorous feeding sick them, and many did not support the European power. Did not have the Guarani tradition have been Hunter village. Their ancestors lived on leaves and weeds, cassava and sweet potatoes. All that was the ancient Guarani vegetalismo is clearly indicated by another tradition that Rochefort has been transmitted to us, very old tradition among them, according to which their ancestors were not fed but of herbs or herbs and natural fruits of the Earth. The Guarani never ate eggs of any kind.