Gaining

Is there a term for wanting to be fattened by feeders who are 400-600 pounds?

No, I don't believe there is such a term. Although, the terms that do exist aren't mutually exclusive, and multiple terms can of course apply to one individual.

The only specific term I can think of that actually combines two preexisting terms is "mutual gainer" since that combines being a feeder with being a feedee.

That said, there's definitely some individuals who are 400+ lbs who may not necessarily be interested in getting bigger, at least not on purpose but nevertheless love the idea of making someone else as fat as they are, or even bigger.

No, I think it's just a case of liking what you like.
2 years