riddle

a man can eat bread, meat, spinach, pears, and cream.

he cannot eat fish, soup, apples, or pizza. why???

i need to know by tomorrow so i don't COMPLETELY lose the game of "stump the teacher" that we played at the end of physics today.

because i already didn't know that emmitt smith accumulated 18,000 rushing yards in his career. or the names of all the caesars that they are apparently learning in their history class right now. so i need to redeem myself.