Ramdomized crossover: The primary purpose of this study was to compare the effects of a very low-carbohydrate and a low-fat diet on fasting blood lipids and postprandial lipemia in overweight men. In a balanced, randomized, crossover design, overweight men consumed 2 experimental diets for 2 consecutive 6-wk periods. One was a very low-carbohydrate (<10% energy as carbohydrate) diet and the other a low-fat (<30% energy as fat) diet. Both diets had the same effect on serum total cholesterol, serum insulin, and homeostasis model analysisinsulin resistance (HOMA-IR). Neither diet affected serum HDL cholesterol (HDL-C) or oxidized LDL (oxLDL) concentrations. The very low-carbohydrate diet was more effective at improving characteristics of the metabolic syndrome as shown by a decrease in fasting serum TAG, the TAG/HDL-C ratio, postprandial lipemia, serum glucose, an increase in LDL particle size, and also greater weight loss.