Date of Graduation

5-2025

Document Type

Thesis

Degree Name

Bachelor of Science in Public Health

Degree Level

Undergraduate

Department

Health, Human Performance and Recreation

Advisor/Mentor

Rosa-Caldwell, Megan

Committee Member

Murach, Kevin

Abstract

Background: Anorexia nervosa (AN) is a physiological and psychological disorder characterized by a decrease in nutrient intake leading to decreased muscle area, decreased bone density, and decreased fat area. There have been minimal studies on the long-term effects of AN, but there is reason to believe that AN can significantly alter muscle area, bone density, and fat area for an extended period after recovery. In this research we will look at the long-term effects of AN on muscle area, bone density, and fat area in rats. Purpose: The purpose of this study was to determine the effects of AN on muscle area, bone density, and fat area following a long term recovery period. We hypothesize that after long-term recovery from induced anorexia, bone, and muscle density of the AN rats will not match the muscle and bone density of the CON rats. Methods: We induced 15 female rats with AN beginning at 8 weeks of age for 30 days by decreasing their food consumption. We had another 15 female rats as control (CON) where we did not restrict food consumption. Before and after the 30 days we used peripheral quantitative computed tomography (pQCT) to image muscle area, bone density, and fat area data for both AN and CON rats. We continued to image muscle, bone, and fat data using the pQCT machine every month post recovery for 5 months total. Results: Directly after food restriction, AN rats had smaller muscular cross sectional area (CSA) compared to controls (~0.622 cm2 at p< 0.05). 1 and 2 months after recovery, AN rats had smaller CSA compared to control (~0.162 cm2 at p< 0.05 and ~0.226 cm2 at p< 0.05, respectively). 3 months after recovery, AN rats no longer had a significantly different CSA compared to controls. Directly after food restriction, AN rats had lower bone density compared to controls (~94.51 g/cm2 at p< 0.05). 1 and 2 months after recovery, AN rats had smaller CSA compared to control (~83.72 g/cm2 at p< 0.05 and ~56.55 g/cm2 at p< 0.05, respectively). 3 months after recovery, AN rats no longer had a significantly different bone density compared to controls. Directly following food restriction, AN rats had significantly smaller fat CSA compared to controls (~0.169 cm2 at p< 0.05). After 5 months of recovery fat area still does not fully recover following AN (~0.077 cm2 at p< 0.05). Discussion: The results of the study are consistent with past finding that individuals with AN show a decrease in both muscle area, bone density, and fat area directly following simulated AN. The data suggest that individuals with AN do not fully recover muscle area or bone density until 3 months following AN, meaning recovery is 3 times the AN period. The data also suggests that fat area does not fully recover following a 5-month recovery period, meaning fat area recovery is at least 5 times the AN period. Overall, the findings in this study showed that AN has a long-lasting effect even post recovery. More studies may be needed to investigate how AN history affects natural muscle atrophy associated with aging.

Keywords

Anorexia nervosa; long term recovery; muscle area; bone density; fat area; physiological effects

Download

Available for download on Monday, May 01, 2028

Share

COinS