Raw meat and raw vegetable juice require opposite digestive environments — respectively acidic and alkaline — and would cancel each other's digestion if consumed too close together.

Our body is by default in an acidic state. "You've got 2300 varieties of bacteria in the mouth and they're all acid." — Aajonus. When we drink raw vegetable juice, it alkalizes the digestive environment, and it takes time to revert back to acidic.

Morning exception: the body is much more acidic from overnight detoxification, so if having celery juice before raw meat in the morning, only 45 minutes are needed instead of a full hour. That applies only once in the morning.

Raw milk and raw eggs are usually not concerned by this rule — they can sometimes be eaten at the same time as celery juice, because they are less acidic than meat.