Annad bhavanti bhutani parjanyad anna-sambhavah
yajnad bhavati parjanyo yajnah karma-samudbhavah
(Karma Yoga, Text 14, Ch 3)
Meaning: All living bodies subsist on food grains, which are produced from rains.Rains are produced by performance of yajna (sacrifice), and yajna is born of prescribed duties.
The devotees of Lord, who are in divine consciousness, offer food to divine and then eat- a process which nourishes the body spiritually. By such action not only are past sinful reactions in the body vanquished, but the body becomes immunized to all contamination of material nature. When there is an epidemic disease, an antiseptic vaccine protects a person from the attack of such an epidemic.Food offered to Lord and then taken by us makes us sufficiently resistant to material affection, and one who is accustomed to this practice is called devotee of the Lord. Therefore, a person in divine consciousness, who eat only food offered to divine, can counteract all reactions of past material infection, which are impediments to the progress of Self-Realization.