Dyslipoproteinemia, a risk factor for atherosclerosis, has been described in anorexia nervosa (AN). To assess whether dyslipoproteinemia is present in our AN population, and to investigate the effect of controlled refeeding, we prospectively examined lipid profiles in 16 hospitalized adolescents with anorexia nervosa on admission and at discharge with a body weight of 90% of ideal. Healthy high school females served as controls. Total cholesterol concentration was not different from controls at either time, and there was no change with weight restoration. Triglyceride levels decreased significantly with treatment, and at discharge, levels were significantly lower than controls. High-density lipoprotein-cholesterol (HDL-C) levels increased significantly with weight gain, and were significantly higher than controls at discharge. Apoprotein A1, the major structural protein of high-density lipoprotein, was also significantly higher among the AN patients after weight gain. Low-density lipoprotein-cholesterol (LDL-C) values did not change, but apoprotein B was significantly higher than controls at discharge. The dyslipoproteinemia demonstrated in our patients was characterized by elevated HDL-C and apoprotein A levels with normal LDL-C and low triglyceride concentrations. These changes were accentuated by restoring body weight.