At each of the three lab visits, body weight and percent body fat (Tanita BIA scale) will be measured. Height will be measured at the pre-study visit. At each lab visit, subjects will also record responses to 6-week retrospective symptom logs. At the pre-study and 6-week study visits, subjects will be given 6-week daily log books, the Wisconsin Upper Respiratory Symptom Survey (WURSS-24), to assess symptoms related to the common cold. Subjects will turn this in during the 6-week and 12-week visits. Subjects will fill in a 6-week retrospective WURSS-24 during visit 1. Subjects will be interviewed by the lab staff at weeks 6 and 12 to determine whether there have been any changes in their medical history or medication use.