Objective: Given the number of college students with a normal BMI decreases 9-12% throughout the college experience, we wanted to model the traits responsible for behaviors impacting body composition in college-age women. Participants: Participants (n = 141) were recruited from a freshman-level nutrition course between August 2016 and May 2018. Methods: We built a path analysis model using variables from online questionnaires and lab visits. We grouped participants by median split of aerobic fitness and evaluated model fit. We defined statistical significance as p < 0.05. Results: The model provided an adequate representation of the data (CFI = 0.921). Aerobic fitness was the strongest predictor of body fat (p < 0.001) in both high-fit (-0.440) and low-fit (-0.469) women. Body dissatisfaction demonstrated relationships with body fat previously established in athletes and clinical populations. Conclusion: Physical activity to improve aerobic fitness appears most effective at maintaining healthy body composition in this population.