Effects of Anorexia Nervosa on Muscle Quality Following Long-Term Recovery in Rats

Anorexia nervosa (AN) is physiological and psychological disorder characterized by reduced nutrient intake leading to a decrease in fat and muscle area. A decrease in muscle area increases risk of musculoskeletal injuries and fractures contributing to higher health care costs. There have been limited studies on the long-term effect of AN following weight recovery. Purpose: Compare muscle health between simulated AN and subsequent long-term recovery and control rats over a two month recovery period. Hypothesis: AN will result in muscle loss that will not resolve following recovery. Methods: Female Sprauge Dawley rats (age=8 weeks, n=15) underwent simulated AN for 30 days by decreasing their food consumption by ~50-60%. Afterwards, rats were allowed unrestricted access to food, simulating recovery. Ad libitum fed rats served as controls (CON, n=15). Peripheral quantitative computed tomography (PQCT) was used to image muscle cross-sectional area from both CON and AN rats at various recovery time points. Data was analyzed by comparing CON and AN at various time points with pre-planned T-tests. Significance was denoted at p<0.05. Results: Directly after food restriction, AN rats had smaller muscular cross sectional area (CSA) compared to controls (~0.622 cm 2 compared to CON p<0.05). 1 month after recovery, AN rats had smaller CSA compared to controls (~0.162 cm 2 at p<0.05). 2 month after recovery, AN rats still had smaller CSA when compared to controls (~0.226 cm 2 at p<0.05). Conclusion: After two months of recovery, CSA remained significantly lower in AN rats compared to CON rats, suggesting that muscle area does not fully recover post-anorexia nervosa, even after an extended recovery period. University of Arkansas Exercise Science Research Center, University of Arkansas Integrative Metabolic Research Center and University of Arkansas Honors College Grant. This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.