Background: The recommendation to lower saturated fat intake is often interpreted as requiring the elimination of beef to control or lower serum cholesterol levels. The study hypothesis was that the Step I Diet (8% to 10% of energy intake from saturated fatty acids) containing beef would have the same effect on plasma lipid levels of hypercholesterolemic men as a like diet containing chicken.
Methods: Thirty-eight free-living hypercholesterolemic (otherwise healthy) men completed a 13-week dietary intervention study. Subjects consumed their usual diets for 3 weeks, followed by a 5-week stabilization diet (18% of energy intake from saturated fatty acids), before randomization to one of two test diets for 5 weeks. The test diets contained either 85 g of cooked beef (8% fat) or 85 g of cooked chicken (7% fat) per 4184 kJ and had 7% to 8% of energy from saturated fatty acids. All food was supplied during the stabilization and test diets.
Results: The beef and chicken test diets both produced significant decreases in average plasma total cholesterol level (0.54 mmol/L [7.6%] for beef and 0.70 mmol/L [10.2%] for chicken) and low-density lipoprotein cholesterol level (0.46 mmol/L [9%] for beef and 0.55 mmol/L [11%] for chicken). Changes in average levels of plasma total cholesterol, high-density lipoprotein cholesterol, triglyceride, and low-density lipoprotein cholesterol were not statistically different (smallest P = .26) between the beef and chicken test diets. The average triglyceride level did not change for either test diet group.
Conclusions: In this short-term study, comparably lean beef and chicken had similar effects on plasma levels of total, low-density lipoprotein, and high-density lipoprotein cholesterol and triglyceride. We concluded that lean beef and chicken are interchangeable in the Step I Diet.