Using data from the Stanford Coronary Risk Intervention Project (SCRIP), the following specific questions were examined : 1. Did the risk reduction program change specific HDtL subclasses as compared to controls? 2. Did the HDL gradient gel profile characterize men most likely to benefit from multifactor risk reduction? 3. Did HDL-subclasses change significantly in patients that reduced fat intake, reduced body weight, or who took one or more of the following medications: colestipol, nicotinic acid, clofibrate, probucol, gemfibrozil, fenofibrate, lovastatin, guar gum or fish oils? 4. What were the cross-sectional associations of HDL-subclasses with adiposity, fasting and post-load insulin and glucose, diet and medications at baseline? Preliminary analyses suggested that: 1) During the trial, men in the treatment group increased HDL2b; 2) the special intervention was most effective in reducing coronary disease progression in subjects with a baseline predominant HDL-peak diameter below the median; 3) HDL- subclasses were more strongly influenced by diet and adiposity than by drugs during the trial; 4) carbohydrates, alcohol and caffeine were associated with specific subclasses at baseline.