I am going to only eat food from Wendy's to get fat.
You will probably be able to do this pretty quickly eating only Wendy's.
I am curious about how fast do I get fat and if all I care about is weight. I feel like an experiment
It might be a fun experiment but it's not really healthy to get fat on purpose especially eating only fast food. You will develop health problems and maybe irreversible effects that you will regret later on.
I have time for it later.
Just think you should reconsider the long term consequences here. Is it really worth it to gain all of that weight just for an experiment? Fast food is pretty bad for your body long term.