Do I have to be vegetarian to take the vow?
We are all part of the food chain. The Upanishads say “ We are tomorrows food.” Eating habits are based on culture, geography and influenced by religion. It is well known that if you give only vegetarian food to indigenous Inuit people, who have survived for eons on whale blubber, you will quickly see the deleterious effects of switching to a vegetarian diet. They become uncharacteristically ill-tempered, their teeth decay, and the incidence of heart attacks increases dramatically. Another study published in Lancet years ago showed that when people were forced to switch to a vegetarian diet because they had high risk factors for heart disease, but were not prepared emotionally and psychologically for the change, their rate of heart attacks actually increased rather than decreased.
In general, it is obvious that a vegetarian diet is healthier, it is better for ecology, and less violent on life as a whole. However, what is best for us as an individual cannot be dictated by general principles or statistics. You must do what you are emotionally and psychologically prepared to do. Childhood habits that are culturally ingrained can be difficult to break, and their impact cannot always be overridden by will power, nor from a health standpoint should they necessarily be overridden. Find the path that works best for you. Being a non-vegetarian should not prevent you from taking the vow.
Deepak Chopra

