This sit is very, very hard to navigate but it seems like there may be some good ones hidden in the archives
Here's a pretty decent story I enjoyed
https://archiveofourown.org/works/8583871?show_comments=true&view_adult=true&view_full_work=true#comments

Please post your favorite stories from the site, I'd love some basic BBW weight gain
If you have any tips on how to find good content, please share, as the tags and simple searches dont seem to work very well.

Another good one

https://archiveofourown.org/works/12494288/chapters/29276628#workskin

Hey. Since I don't want to post my stories in more than one thread I'll list them here and tag them.

https://archiveofourown.org/works/37161559
>Spamton NEO from Deltarune (post pacifist), greentext format, male weight gain/weight loss, emotional eating, binge eating, minor health issues, drama
https://archiveofourown.org/works/39165138/chapters/98262675
>Spamton (Addison/AU), prose format, male weight gain/weight loss, failed/successful dieting, mild groping, emotional eating, binge eating, drama
https://archiveofourown.org/works/41580918/chapters/104293053
>Spamton (Addison/AU), femAnon, greentext format, male and female weight gain/weight loss, role reversal, emotional eating, binge eating, minor hedonism, mild groping, romance with some drama

The third one is based on the second.

Hasn't been updated in awhile, but one authors keeps making stuff.

https://archiveofourown.org/works/27524203