I think, growing up, scenes involving WG just caught my attention more than others. There were specific scenes in cartoons like The Simpsons and even Courage the Cowardly dog (some episode where Eustace got turned into a dinosaur?) that I fixated on when I was young. I recall hoping for the “fat” episodes to air whenever re-runs were on TV 
I don’t think it was until I was maybe 8 or 9 when I felt different–embarrassed, actually–for really liking the fat dragon transformation scene from that sequel to the animated film “Anastasia”. There were chuckles and such among my family during that scene, and I was just like 
lmao!
I believe that the event that really cemented it in my psyche was when I gained a little bit of weight myself over a summer during my middle school years. It wasn’t like I became fat or anything, but I noticed that if I puffed out my middle, it wasn’t flat anymore. Wires got crossed, I discovered deviantArt, found out that there was fat/wg art of anything, practiced my own drawing skills, and so on. I wouldn’t attempt to purposefully gain weight until several years later into my late-teens, which proved to be a horrendous experience. The amount of money I spent to eat so much and the effects on my health and mentality were not worth the comparatively-short mirror-ogling sessions. I guess by living through that, I managed to un-cross a wire or two, lose a bunch of weight, and even have a completely changed lifestyle now. I no longer have a desire to be fat; today, you wouldn’t be able to tell that I used to be overweight!