I'm giving the benefit of the doubt, and assuming that this isn't just bait.
Please fucking do not. Your fetishes and what you do with them are your business, but when you're talking about a 100+ lb. weight gain, let alone 300, I don't think you've even begun to consider the health consequences, in neither the short nor long-term.
I cannot be more clear than this: If you put on that much weight, you will die young.