chubbyTrainer:
I don't know how niche this is, but I'm a female personal trainer and feeder who enjoys helping people with medical play, trainer, or humiliation fantasies.
I was a personal trainer for several years (still do it from time to time) and I love doing this. It was so much fun when I'd have a feedee and we'd see her friends and family and they were so confused as to how she was with me all the time but still getting fatter.