Questioner: So is it certain that food does have an effect on the mind?
Dadashri: Everything is the effect of food. Eaten food turns into "brandy" (that which produces a deleterious effect on a person's awareness) in the body. These effects are directly linked with spiritual awareness. Heavy or excessive food decreases spiritual and mental awareness. Even pure vegetarian food has this effect but to a lesser degree. Rich and sweet foods are not considered good foods because they increase these harmful effects. But people turn these principles around for their own convenience.
Questioner: Does eating meat affect one's spiritual thinking?
Dadashri: Of course! Non-vegetarian food is sthool (gross, heavy, coarse), and does not allow the development of one's spiritual intellect. If you want to progress in spiritually you must eat vegetarian food, which is light and does not create intoxication. It also helps in increasing awareness. In general people have no awareness whatsoever!
Foreign scientists cannot understand what I am saying and it is difficult for them to believe it, although they do say that it merits consideration. I tell them that it will take a long time for them to understand it, because they have consumed so many chickens and other meats. Eating meat creates a dense covering over the Soul. For one to understand this Gnan (knowledge), a pure vegetarian diet is required, because the coverings from the vegetarian diet are comparatively thin, so one is able to maintain a higher awareness.
Book Name: Non-violence ( Entire Page #48)