I'm going to purposely give myself food poisoning
Why would you want to get food poisoning?
I'm kind of impulsive and I sometimes do things on a dare.
There is no good reason to give yourself food poisoning. Purposely making yourself sick with food poisoning is wrong as it can lead to health problems and expensive medical treatment. You should not act impulsively and instead think about your behavior more rationally.
Scary, why is it so bad to do this?
It is bad because like I said, it could really harm you! You should want the best for yourself and not try to intentionally bring harm.