Repeated observation of eating in the natural environment was used to compare the behavior of two obese college students with their normal weight roommates. The number of calories consumed, the frequency of obtaining seconds, the frequency of cleaning the plate, and the time spent eating were assessed. Obese subjects ate larger meals and a greater number of snacks than their normal weight partners according to both direct observation and self-report measures. Self-report and direct observation were equally accurate measures of caloric intake, but self-recording seemed to alter the subject's normal eating habits. Repeated observation in the natural environment may be a useful technique for studies of normal-obese differences and individualized assessments of eating habits.