早食い競争って英語でなんて言うの？

This is a contest to see who can eat the most food in a limited amount of time.

"Competitive" is when you want to be the best
"Contest" is a competition
"Speed" is to see who can do it the fastest

1. A food race. This indicates that people will be consuming food in a race format where the speed of eating is critical to decide the winner.
2. A food eating contest. this indicates that there is some form of competition involving food. The key factor may be speed or it may be quantity - or a combination of the two that are the key factors.
3. This indicates that people will be consuming food in a race format where the speed of eating is critical to decide the winner.

-Eating Contest
This is a competition to see who can eat the most food in the shortest amount of time.

-Fastest eater contest.
This is a competition to see who can eat the given food the fastest.

A "eating competition" is a race where people try to eat more than another. The one who eats the most or the fastest would be the winner.

A contest where people have to eat as fast as they can; you can use the phrases "eating contest" or "eating competition".
For example, you can say:
-I am going to an eating competition for the first time this Saturday
-I am competing in an eating contest on Saturday