Responses
http://www.mangago.me/read-manga/hoppe_ni_himawari/
http://www.mangago.me/read-manga/dame_bl/mh/c011/
http://www.mangago.me/read-manga/koi_no_enchousen/
http://www.mangago.me/read-manga/ai_no_gebokutachi/ (ch3, he loses weight but gains it back)
http://www.mangago.me/read-manga/sweet_bitter_candy/ (use to be chubby)
the first three are shounen ai, but cute.
Can somebody recommend me a yaoi in where the some or the uke are like fatty/chubby ? XD hehehe