One day I found an article about the various things that are used in inorganic farming and food production, and their other uses, such as rat poison, napalm and paint thinner, to mention a few. I asked Srila Prabhupad if I could read Him that short article, and He agreed. As the facts were presented, He opened His lotus eyes very wide and said with great power... "NEVER feed me any of that!"
...Another question I asked Him one day was whether I should pay any attention to what I was eating, ingredient-wise, or simply accept prasadam because it was prasadam, and not care about the ingredients. Srila Prabhupad, in His often jovial way, said with a stern face... "You should only take prasadam and not care about the ingredients" and after waiting for a few seconds He said with a big smile... "If you are Rupa Goswami. But you are not Rupa Goswami…you are a neophyte devotee, as are all my disciples, and as a neophyte you must be very careful to eat what makes you healthy and avoid anything that makes you sick or affects your devotional service in any negative way. Eating very simply is the best diet for Krishna consciousness."
All glories to His Divine Grace Srila Prabhupad.
From Nanda Kumar Prabhu