Jackie often tries to achieve greatness in ways that don't necessarily merit chapters of their own. In this case, she's decided to train to be a competitive eater. It's definitely a loaded situation, showing a fat girl eating a whole bunch. Media tends to portray fat girls two ways. 1: constantly eating, very greedy people or 2: always on a diet, and good because of it. A lot of times, fat girls are only acceptable if they're doing the "right" thing trying to "improve" themselves by not eating. But Jackie, she eats. A lot. And that has no bearing on her moral character.
After this page, she barfs during dog 10, and decides competitive eating is not for her.