An integral element of this preparation is to undertake a diet intended to reduce refined sugar, salt, oils, pork, fat, fermented alcoholic beverages, and hot spices in the system in order to realize the greatest potential benefits from the Ayahuasca medicine.

Abstinence from sexual orgasm is an integral part of this diet and is considered, along with abstinence from pork and alcohol, to be the most important aspects of the diet.  This diet should commence at least three days before the first Ayahuasca ceremony and continue for three days after the final ceremony (see comments regarding pork).

Pork in particular is considered to be impure and is studiously avoided by Ayahuasca practitioners. Complete abstinence from pork and lard for at least two weeks prior to the first ceremony is required of participants to lessen the impact of the purge and avoid possible unpleasant side effects. This abstinence should continue for at least two weeks after the last ceremony.

In the Peruvian Amazon, the most rigorous shamanic diet consists mainly of certain types of small scaly fishes boiled with rice, plantains and yuca (manioc).  No salt, sugar, oil, ají (hot chili) or sexual activity is allowed during months of jungle isolation from the outside world. This is the diet undertaken by apprentices hoping to become shamans. This diet is very difficult and few succeed in strictly keeping to it for more than a few weeks.  The social and sexual segregation required is the primary reason so few maintain the diet for long periods.  It is not necessary to enter this demanding dietary regimen to undertake personal cleansing and spiritual transformation with Ayahuasca under the guidance of genuine shamanic healers (curanderos).

In the initiatory diet for those seeking personal cleansing and healing, the diet need not be as rigorous and may include chicken, fish, wild game meat, fruits and vegetables.

The holistic cleansing benefits and power of the visionary experiences are often greatly enhanced by commitment to these preparations, for such reflects your INTENT, which is the single most important personal factor in work with Ayahuasca.

(Written from Outside Source)