The answer should be 2 men.
Here is the reason.
∵2 men catch 2 fish in 2 minutes.
∴we can separate to this
one fish------one man------ two mintues
one fish------one man------ two mintues
(Right? the important one is counting time should be together. Have a think.^^)
two fish------two men------two mintues
Then, let's say Y men could catch 500 fish in 500mintues.
so,should be:
500 fish------Y men------500minutes
then, according to the rate.
250 fish------one man------500min
250 fish------one man------500min
finally.
500 fish------two men------500min
(If you not sure, you may have some try with your friend. Maybe try some sugar not too much. record the time and rate. REMEMBER don't eat too much ^^)
Hope you can understand that.
