Hyperuricemic-hyperlipidemic patients exhibit decreased renal excretion of urates relative to purely hyperuricemic patients; also, very low density lipoprotein (VLDL) levels are inversely proportional to the amount of urate excreted. Based on this knowledge, the aim of this study was to alter VLDL levels by dietary manipulation and assess its effect on uric acid levels and renal excretion of uric acid. Thirty-six men were studied in 2 groups consisting of 20 primary hyperuricemic (group I) and 16 primary hyperuricemic-hypertriglyceridemic patients (group II). The patients were analyzed for apoproteins and lipoproteins, urate levels, and renal excretion of uric acid in a first, basal determination, after 3 weeks of a 1200-Cal diet, and after another 3 weeks of a 2500-Cal diet. After the 1200-Cal diet, patients in group I exhibited significantly decreased levels of cholesterol (P < 0.05) and apoprotein CIII (P < 0.05). There were significant differences in renal excretion of uric acid (P < 0.05) between the basal and third determinations. Patients in group II exhibited significantly decreased levels of triglycerides (P < 0.01), VLDL cholesterol (P < 0.01), VLDL triglycerides (P < 0.01), and VLDL apoprotein B (P < 0.05) after the 1200-Cal diet; all of these parameters returned to values similar to the basal levels on completion of the 2500-Cal diet. With regard to purine parameters, the low calorie diet led to significantly increased fractional excretion of uric acid (P < 0.01) and uric acid clearance (P < 0.01), both of which decreased significantly to values near basal after the 2500-Cal diet. The results obtained in this study reveal that the decreased levels of triglyceride and VLDL components that arise from a low calorie diet are accompanied by increased renal excretion of urates and that the increase in the amount of this type of lipoprotein particle with an increase in dietary energy offsets the increase in renal excretion of urate.