https://www.youtube.com/watch?v=QpP1hfEOO00This man can eat an apple in one bite. If everyone could do be trained to do that, the answer would be mass of Earth divided by the mass of an apple.
mEarth = 6*10^24 kg & mApple = 0.1kg so mass of the apple earth = 6*10^25 regular apples.
60000000000000000000000000 bites at the minimum.