This study will compare the effects of cooked, ground beef to those of beef protein isolate on blood and muscle proteins.

STUDY OBJECTIVES Primary: To compare the effects of consumption of a 3-ounce serving of beef to that of a 20g serving of BPI on skeletal muscle synthetic and breakdown rate in healthy elderly subjects.

Secondary: To investigate the effect the study products on plasma levels of amino acids, insulin, and glucose in healthy elderly subjects.

Inclusion Criteria:

• Healthy male or female.
• Age 60 years or older.

Exclusion Criteria:

• Any (history of) gastrointestinal disease that interferes with GI function
• Diagnosed and active treatment of Diabetes Mellitus type I or II
• History of congestive heart failure
• Recent (6 months) hospitalization for heart disease treatment or management (e.g. PTCA, stent, surgery)
• Myocardial infarction in the past year
• Infection or fever in the 7 days prior to enrollment
• Current use of corticosteroids, growth hormone, or testosterone
• Adherence to a weight loss diet
• Use of protein-containing or amino acid-containing nutritional supplements within one week of enrollment
• Current alcohol (>7 ETOH per week) or drug abuse
• Platelet count (PLT) < 100,000
• History of hypo- or hyper-coagulation disorders including use of a coumadin derivative
• Currently taking anti-thrombotics and cannot stop for 7 days (i.e. medical indication)
• Allergy to local anesthetic
• Blood hemoglobin < 9.0 g/dL
• Investigator's uncertainty about the willingness or ability of the subject to comply with the protocol requirements