Weight loss commonly occurs in patients with COPD, negatively influencing their quality of life, treatment response and survival. Loss of muscle protein is generally a central component of this weight loss and independently increases mortality. This study will provide relevant clinical information in regards to the anabolic properties of specific dietary substrates and their co-active anabolic effects. Hypotheses: 1) That supplementation of a hydrolyzed casein-based protein meal with the addition of carbohydrates is more anabolic than a hydrolyzed casein-based protein meal without carbohydrates in COPD patients and healthy older adults; 2) That leucine addition to a hydrolyzed casein-based protein meal only enhances the protein anabolic response in COPD patients and healthy older adults when carbohydrates are not added to the protein meal; 3) That COPD patients have a more efficient protein anabolic response to a hydrolyzed casein-based protein meal than healthy older adults.