That is a very good question and I have no answer for it.
The only thing for me that is even close to a fetish is womens feet I just love them.
As far as me being over weight thats just my preference.
I don't dwell on it or think about it all day.

For me the more I eat the more I can eat if that makes sense.
I find when I'm in a gaining cycle I eat even when I'm not hungry.
It just looks yummy so I eat it.
IDK what you call that medically but it happens to me.
I'm a binge eater so I guess that falls under a binging persons profile.

I think the ideas and the feelings are very erotic.
One: feeling really full and having someone rub my belly is very nice.
Two: knowing over indulging will lead to weight gain.Kind of the OO I have been a bad girl thing.
Three: Sex on a full belly is pretty close to as good as it gets.

I'm sure there are some on you tube as well.
Google couples feeding images.

I got that a lot from co workers and my Mom the first time I started gaining.
Came back home after working out west with 30 extra pounds and a huge muffin top.

That would be nice I agree.

1 When I walk my belly goes back and forth and up and down.
2 Have a short top on and let my belly hang out for the world to see.
3 when my thighs rub together wearing tight jeans.

Vin did get quite a pudge for that movie.

I tried the weight gain powders but they tasted horrible to me and gave me a belly ache.
A good DQ blizzard 3 times a day worked for me.Yummy flavors and tons of calories.

You sound bi curious which is fine/normal.
Fat sexual is a good term whoever coined that term is brilliant.
I find both sexes attractive even more so if the are on the plus side.