Date of Graduation


Document Type


Degree Name

Doctor of Philosophy in Food Science (PhD)

Degree Level



Food Science


Jamie I. Baum

Committee Member

Sami Dridi

Second Committee Member

Walter G. Bottje

Third Committee Member

Yan Huang

Fourth Committee Member

Sun-Ok Lee

Fifth Committee Member

Luke R. Howard


Chronic Disease, Leucine, Obesity, Sarcipenia, Skeletal Muscle


Prevalence of chronic diseases in the United States keeps increasing in recent years. There are approximately four in ten adults having chronic diseases in America. Chronic diseases include obesity, aging, heart diseases, cancer and many others. This thesis mainly focuses on obesity and aging. Skeletal muscle performance is impaired in obesity and aging conditions. One common reason causing this could be higher fat mass and lower muscle mass. However, there is no study showing what pathways are involved in the imbalance of body composition. Therefore, the first objective of the thesis is to determine gene expression of selected pathways in the skeletal muscle from young and old, lean and overweight/obese participants. Leucine has been shown to activate protein translation initiation pathway mTORC1 in skeletal muscle. Further, mTORC1 is also known for regulating a variety of cellular pathways. Thus, the second objective of the thesis is to determine the effect and mechanisms of leucine supplementation on preventing intracellular lipid accumulation in skeletal muscle cells.