The effects of stearic acid on metabolism must be evaluated for stearic acid as an isolated dietary constituent and for stearic acid as a component of a natural fat. Beef products are the most common source of dietary stearic acid in the United States. Two components of beef products, beef protein and beef fat, can potentially impart cholesterol-raising properties. Protein has minimal effects on cholesterol concentrations in humans, but studies suggest that beef fat raises serum cholesterol concentrations. Because beef fat is 19% stearic acid, the cholesterol-raising potential of beef is not as great as predicted by its total saturated fatty acid content. However, beef tallow is hypercholesterolemic compared with fats containing less cholesterol-raising saturated fatty acid. Therefore, curtailment of beef tallow in a cholesterol-lowering diet seems appropriate. Data suggest that lean beef is no more hypercholesterolemic than chicken or fish and, therefore, lean beef need not be eliminated from cholesterol-lowering diets.