Purpose: High protein diets have become increasingly popular among the general public. High protein diets have been postulated to negatively impact lipid levels, yet new research suggests that lipid changes may in fact be due to fat content in the diet or active weight loss. The purpose of this study was to compare the effects of a higher protein diet followed for twelve weeks on lipid levels in young, normolipidemic, normogylcemic and previously sedentary participants. Design: Forty-eight sedentary participants who had been inactive for the previous three months were randomly assigned to one of two diet groups consisting of Diet 1 (40% carbohydrate, 30% fat, 25% protein) and Diet 2 (40% carbohydrate, 30% fat, 25% protein and caloric restriction). Each diet group followed recommended aerobic exercise prescriptions. Approximately 20 ml of blood was collected from each participant after fasting for 12 hours using standardized venipuncture techniques in the antecubital vein in the bend of the elbow. Blood was donated at baseline (week 0) and at 12-weeks. Blood analyses included total cholesterol, HDL, LDL, triglyceride and total cholesterol/HDL ratio. Participants had a twenty-minute session with a counselor every two weeks for the entire 12-week study period for a total of six visits. The counselor checked how well each participant was following the dietary and exercise recommendations and suggested changes to better fit those recommendations as necessary. The counselor also monitored dietary and exercise data entry, specifically looking for program adherence. Results: Analysis of variance (ANOVA) revealed no significant differences at baseline for each lipid measure suggesting two groups that were homogenous. Also ANOVA revealed no significant differences in aerobic exercise minutes per week between groups (p=.76). Significant differences in body fat levels as measured by DEXA occurred in Diet 1 (-6.86%, p<.001). All other groups did not have a significant change in body fat levels. The only significant changes in lipid levels occurred in Diet 2 with an increase in HDL levels (+5 mg/dL, p<.01). Analysis of covariance (ANCOVA) and post-hoc analyses (LSD) revealed no significant weight loss in either group (p=.24) suggesting differences in body fat in Diet 1 may have been offset by an increase in lean tissue. These findings suggest that body fat loss while consuming a higher protein diet and exercising may play a role in lipid management even when active weight loss did not occur. Keyword(s): exercise/fitness/physical activity, health promotion, nutrition