The investigators are interested in the effects of two different diets on asthma health. The first, a prudent diet, consists of a high intake of fruits and vegetables, whole grains, fiber, omega-3 fatty acids, low-fat dairy products, and overall high levels of antioxidants (which may protect the lungs and the body against inflammation in patients with asthma). The second, a Western diet, consists of a high intake of processed foods, fast foods, sweets, omega-6 fatty acids, and a low intake of fiber (which may promote inflammation in the lungs and the body of patients with asthma).