Purpose. This study aims to examine the relationship between physical activity, eating attitude, and bigorexia nervosa among university students. Method. A questionnaire form consisting of sociodemographic characteristics, eating habits, the Eating Attitude Scale (EAT-40), the International Physical Activity Questionnaire (IPAQ), and the Muscle Appearance Satisfaction Scale (MASS) was conducted on undergraduate students at Üsküdar University. Results. There were 1006 students who participated in this study with a mean age of 22.58 ± 2.87 years. The median “muscle appearance satisfaction” score of the obese students was statistically higher than the normal weight and underweight students. The median score for “Obesity Anxiety” was statistically higher in underweight students than in obese ones. A one-unit increase in IPAQ scores was related to an elevation of 24.9% in the MASS and a decrease of 17.9% in the EAT-40 scores, while a one-unit increase in MASS scores was related to a reduction of 12.5% in the EAT-40 scores. Conclusion. Eating attitude is associated with bigorexia nervosa, and as MASS scores increase, EAT-40 scores decrease and as IPAQ scores increase, and EAT-40 scores decrease. In other words, as physical activity increases, muscle strength satisfaction elevates, and in parallel with this increase, a positive eating attitude improves.