The study has two parts: first, the investigators compared dyspnea, pulmonary function and exercise measurements between obese patients and control subjects with normal weight; then, the investigators assessed the effects of medical weight loss in the obese group on these parameters. Baseline dyspnea was assessed using the baseline dyspnea index.The effect of weight loss on dyspnea was assessed using the transitional dyspnea index. The main physiologic measurement of interest was the inspiratory capacity (L, measured at rest and during exercise).