Dietary Adherence, Orthorexia Nervosa Risk, Physical Activity Levels, and Body Image Satisfaction in Patients with Neuroendocrine Tumors: A Cross-Sectional Study

Background/Objectives: The global incidence of neuroendocrine tumors (NETs) is steadily rising. While modifiable lifestyle factors impact oncological outcomes, the interplay between dietary habits, orthorexia nervosa (ON) tendencies, physical activity levels (PAL), and body image in NET survivors remains poorly understood. Methods: A cross-sectional study was conducted on a convenience sample of 61 patients with NETs. Validated evaluation tools included the PREDIMED questionnaire for Mediterranean Diet (MD) adherence, the GPAQ for PAL, and the ORTO-15 questionnaire for ON risk. Body image satisfaction and comprehensive clinical features were also assessed. Results: Most participants (75.4%) demonstrated moderate MD adherence. Body image dissatisfaction (32.8%) was significantly associated with a higher BMI (28.86 vs. 24.93 kg/m2, p < 0.01) and reduced PAL (660.0 vs. 1680.0 MET-min/week, p = 0.021, pFDR = 0.042). Notably, moderate MD adherence was linked to a higher orthorexic risk (corresponding to lower ORTO-15 scores) compared to low adherence (p = 0.032, pFDR = 0.078). Somatostatin analog therapy showed no detrimental impact on behavioral parameters (p > 0.05). Conclusions: These findings highlight specific vulnerabilities in NET patients: body image dissatisfaction correlates with higher BMI and lower physical activity, while moderate Mediterranean Diet adherence associates with orthorexic risk, which is localized and was not independent in multivariate analysis. Targeted nutritional and physical activity interventions should be integrated into multidisciplinary NET care.