Cholesterol-lowering effect of a low-fat diet containing lean beef is reversed by the addition of beef fat.

The aim of this study was to differentiate between lean beef and beef fat as risk factors for elevated plasma cholesterol concentrations. Ten healthy weight-stable subjects (five men, five women) participated. Energy intake was kept constant over the 5-wk study. Total cholesterol concentrations fell significantly within 1 wk of commencing the very-low fat (9%) energy from fat) lean-beef (500 g/d) diet (5.91 +/- 0.47 to 4.72 +/- 0.42 mmol/L, p less than 0.001) and rose as beef drippings were added in a stepwise manner in weeks 4 and 5 (5.45 +/- 0.56 mmol/L in week 5). The changes in total cholesterol concentrations were due almost entirely to changes in the concentration of low-density lipoprotein cholesterol levels. These results indicate that it is the beef fat, not lean beef itself, that is associated with elevations in cholesterol concentrations and that lean beef can be included in cholesterol-lowering diets provided it is free of all visible fat and the saturated fatty acid content of the diet is low.