The purpose of this study was to identify cardiac biomarkers of disordered eating. Mean R wave amplitude (mV), mean T wave amplitude (mV), QRS interval (sec), QTc interval (sec), and Tpeak-Tend interval (sec) were assessed via electrocardiography among women with clinical (n = 53) and subclinical (n = 56) eating disorder symptoms versus asymptomatic controls (n = 32). QRS and QTc intervals were significantly longer and mean T and R wave amplitudes significantly lower among women with clinical symptoms compared to asymptomatic controls. QTc interval length was significantly longer and mean R wave amplitude was significantly lower among women with subclinical symptoms versus asymptomatic controls. Decreased mean R wave amplitude yielded a comparable effect size as QTc when differentiating between asymptomatic and subclinical groups and a larger effect size than QTc when differentiating between asymptomatic and clinical groups, representing a promising clinical biomarker.