It was hypothesized that obese individuals respond to unlabeled high arousal by overeating, while no such response was predicted for labeled high arousal states. Obese and normal weight subjects were led to believe that they were hearing their own heart beat, and that it was either fast or slow. A label for this heart rate either was or was not provided, and subjects' eating behavior was measured unobtrusively. The results supported these hypotheses: aroused obese subjects ate more when they could not identify the cause of their arousal than when a label was known. When obese subjects were calm, the presence or absence of a label did not affect their eating. Furthermore, obese subjects showed significant affect reduction following eating. Normal weight subjects were not affected by the presence or absence of an arousal label. Instead, they ate more when they called themselves calm than when anxious, and more when hungry than when full.