Regarding your question about maintaining your body nicely, I think that if you follow our regulations of diet, sufficient sleeping, and keep to the prescribed rules of cleanliness, two baths per day,* then you will be able to keep yourself in proper health. Of course disease will always be there at some time while there is this material body, but this we must tolerate and not be very much agitated by. Actually, the Vaisnava who knows that he is not this body, he does not therefore neglect his body, but he takes very nice care so that he may utilize his body in the service of Krishna. Just like a man may know that he is not his car, so he does not therefore neglect his car, but he will take care of it so it will be able to render service to him. So we must take sufficient care to provide our bodies with its demands, but when disease or other necessary inconveniences arrive, we do not become disturbed because such troubles are simply temporary manifestations.
I hope this will meet you in good health.
Your ever well-wisher,
A.C. Bhaktivedanta Swami
*at least one