Early adherents adopted their dietary laws based on their interpretation of several books of the Bible, like the Genesis ("And God said, Behold, I have given you every herb bearing seed, which is upon the face of all the earth, and every tree, in the which is the fruit of a tree yielding seed; to you it shall be for meat., the Leviticus and Deuteronomy. Though there are different interpretations of ital regarding specific foods, the general principle is that food should be natural, or pure, and from the earth; Rastas therefore avoid food which is chemically modified or contains artificial additives (e.g., color, flavourings, and preservatives). Some also avoid added salt in foods. In strict interpretations, foods that have been produced using chemicals such as pesticides and fertiliser are not considered ital.
In common with religions such as Judaism, Islam, and Ethiopian Christianity, Rasta prohibits the eating of pork. Some Rastas also avoid eating shellfish because, in common with pigs, they are considered to be scavengers. Most Rastas avoid the consumption of all red meat, many do not eat fish or those fish over 12 inches in length, and some are strict vegetarians.
Stricter interpretations also avoid food that has been preserved by canning or drying and even prohibit the use of metal cooking utensils, something that Ayurvedic diet followers also avoid. In this case, only clay and wood cooking pots, crockery, and cutlery are used. Few adherents of ital follow the strictest interpretation; some Rastas do not adhere to them at all.
Rastafarians do not allow alcohol, cigarettes, or coffee. To them, these are drugs that cloud the mind. Rastas, however, do allow cannabis because they believe it causes a strong prayerful state. Some Rastas do not believe in medicine, but many urbanized Rastas allow such practice.