Final answer:
Julia most likely has nonpurging type bulimia nervosa, characterized by binge eating and compensating through excessive exercise, rather than purging.
Step-by-step explanation:
Given the description of Julia's behavior, consuming large meals and then compensating for this overeating by engaging in hours of excessive exercise, Julia most likely has nonpurging type bulimia nervosa. This type of eating disorder is characterized by episodes of binge eating followed by other methods of compensating that do not involve purging, such as excessive exercise, to avoid weight gain. This is distinct from purging type bulimia nervosa, where individuals would typically engage in self-induced vomiting or misuse laxatives, diuretics, or enemas after binging.