- To look for associations between changes in LDL cholesterol and baseline characteristics of patients receiving dietary therapy for hypercholesterolemia. Ninety-six hypercholesterolemic individuals aged 30-65 from three primary care clinics and a worksite clinic received counseling by a physician and/or a dietitian for lifestyle and dietary modifications. Baseline nutritional intake was evaluated using three-day food diaries. Lipoprotein levels were evaluated at six weeks and thereafter every three months for one year. Partial (adjusted) correlations (beta) were calculated between baseline parameters (demographic, anthropometric, nutritional and laboratory) and changes of LDL cholesterol for the short and long term (three and 12 months). The average LDL cholesterol level decreased by 6 +/- 10% (p < 0.001) at the end of 12 months. This reduction was positively correlated with baseline LDL cholesterol level (beta = +0.4, p = 0.001), and negatively correlated with the baseline BMI (beta = -0.2, p < 0.05) and saturated fat intake (beta = -0.3, p < 0.05). The differences between low and high subgroups of baseline LDL cholesterol, BMI and saturated fat intake became apparent only after six to twelve months of therapy and probably result from varying levels of adherence to the dietary regimen. A significant correlation was found between the change in LDL cholesterol after six weeks and the change in LDL cholesterol after 12 months (beta = 0.4, p < 0.001). The probability of successfully reducing LDL cholesterol with dietary therapy can be predicted by baseline LDL cholesterol level, BMI and saturated fat intake, as well as by the response to dietary changes within six weeks of therapy.