Ballmastrz: 9009

Ballmastrz: 9009 is a 2018 animated series that takes place in a post-apocalyptic future where everything surrounds The Game, a violent sport that is said to have ended all war. It follows a losing sports team full of misfits called the Leptons and former star player Gaz Digsy, who due to her bad attitude and partying is forced to join them until they can win. The show is named after a type of legendary warrior that has the power to combine with the talking sports balls and become a powerful robot, and two of the protagonists discover they can do this.

A Shooting Star Named Gaz Digzy Falls Fast and Hard (S01 E1)

We see Gaz Digzy go from being in shape with abs to being out of shape with a large beer belly after partying too much, which she retains for the rest of the series.

Chaste Wing of the Cold Turkey vs. Flaming Fist of Indulgence! (S01 E9)

Gaz has a nightmare where she is being force fed an infinite amount of food. Later in the episode her weight loss is reversed when she attempts to use the secret technique of the Umbilicus.