There is no other religion that emphasizes so much on what we eat, how we eat, when we eat, how much we eat than Jainism. The phrase "we are what we eat" may have been born abroad but it's essence truly lies in the tenets of Jainism.
A religion which believes so staunchly in non violence that what is consumed is based on the least amount of '_Ahiṃsā_' to living being visible and not visible to the naked eye.
Jains consume no products which cause harm to animals right from meat to honey to bread which calls for fermentation. When it comes down to plant foods there too a serious demarcation is made between roots, the consumption of which means death to a large number of living beings, to that produce in which only one life is extinguished.
Fruits and vegetables with multiple seeds are avoided. Foods which are tamasic (dull the body and hence are harmful) such as brinjals also a taboo.
From food, the focus shifts to fasting, which is essential to shedding the karmic baggage one carry from the past. Fasting is not only routine but also seasonal, which prepares the body in anticipation of the changing seasons.