Hitori no Shita: The Outcast
Yi Ren Zhi Xia (一人之下, literally: "Under One Person") with subtitle The Outcast is a Chinese webcomic by Dong Man Tang (Chinese: 动漫堂), illustrated by Mi Er (Chinese: 米二), and published by Tencent. It was been first published under the title name 异人 (Yi Ren, literally: "Weirdo") and with subtitle King of the Weirdo in February 2015.
A collaboration Chinese/Japanese anime television series adaptation titled Hitori no Shita: The Outcast (一人之下, literally: "The Outcast") aired from July 9 to September 24, 2016. A second season began on January 16, 2018, and is simulcast in Chinese and Japanese.
One day, Zhang Chulan is attacked by zombies in a graveyard. In the midst of that situation, he saves the life of a girl, throwing the kitchen knife in his hand in order to kill the enemies. The girl tells Chulan, who is relieved, to face his hardships head on and leaves. However, Chulan later sees that girl again at his university. From that moment, Zhang Chulan's destiny begins to move.
Manga
Episodes
Qimen Kenzou Shinpou (S02E09)
in one match in particular, Feng Baobao (Chinese) or Fū Hōhō (Japanese), began absorbing her opponent's soul into herself by sucking it all in and used herself as a temporary container until the others can come up with a solution, thus inflating her belly in the process.
There often are times when people eat. For most a few times a day.
There are other times when people absolutely stuff themselves. This hopefully doesn't happen as often. But when animated characters do it, it goes right to their tummy and increases their size and figure in a similar manner to filling a balloon. This new-found girth usually goes away pretty easily, but can stay around for a while. A usually-minor form of this is Truth In Television.
Also, there are times when people don't have anything to eat for a long time, and then they play the trope exceptionally straight. They get kwashiorkor.
The girth can also come from water, or even air or helium. In the case of the latter, one also receives other qualities of a balloon.
There is a fetish for this out there. Or So I Heard.
Examples: