A burger is like what, 400 calories?? Maybe 800 with fries and Coke? 1200 on the high end for a basic combo I’d guess. Not a crazy amount if you are mindful about it. Marissa was also decently tall (as an adult Mischa Barton is 5’9”) so her BMR is automatically going to be higher plus she’s a growing teenage girl. And since it was Cali, even if Marissa didn’t enjoy “exercise”, she still lived an active lifestyle. The cast on the whole were regularly shown swimming, walking on the boardwalk and on campus, climbing stairs, running, doing fitness classes, surfing, dancing, biking, skateboarding, etc. They also talked about soccer, lacrosse, kayaking, sailing and horse riding. And Summer (and Ryan?) were into boxing. And of course shopping can include a lot of walking which burns calories. And they probably also did some winter sports too on vacations (I think Summer mentioned skiing with her dad for holidays?).

TBH I think that was sort of a bitchy line to throw in there, especially because Mischa was modeling at the time if I’m not mistaken. Tall girls gotta eat, even the toothpicks.