im guessing organic food is probably one of them,but i really dont know about anything else,
Pretty much organic food, food you grow yourself. There is some organic beef/eggs that is made without any additives. But almost everything you buy will have some sort of preservative to keep the food from going rancid or rotting.
Any unprocessed food. Fresh Whole Fruit, Fresh Whole Vegetables, Whole Grains in their raw form, Meat in its raw, unseasoned, unprocessed form. Most dairy has food additives.
I've done it quite often w/o any major ill effects, sometimes the profile of the tires is higher or lower which changes the handling, of course just changing tire brands does that. I'd run um until I was ready for a new set, just be aware that it might not be perfect for 100% riding.
Foods that don't come in packages!!! Think vegetables, fruits, fish, poultry breast, meats the meat counter. stuff like that. Foods don't necessarily NEED to be organic in order to not have food additives.
Metzlers have a softer compound than the Dunlops. The Metzlers hug the road a little better, but wear out quicker. As a general rule of thumb, do try and use the same types on both wheels. I use Avon Venoms on both my RoadKing and on my Chopper.