We have designed a human-feeding laboratory to be used to study feeding behavior in patients with eating disorders. Twenty-one normal-weight bulimic subjects consumed 29.711 +/- 39.940 MJ (range 0.862-178.632 MJ; 7101 +/- 9546 kcal, range 206 to 42 694 kcal) in 24 h. In comparison, 11 healthy volunteer women, when instructed to eat ad lib for 48 h, ate 7.715 +/- 2.590 MJ (1844 +/- 619 kcal) during the first 24 h and 7665 +/- 1828 MJ (1832 +/- 437 kcal) during the second 24 h. Bulimics and control subjects had a similar number of eating intervals (6.6 +/- 2.6 vs 5.0 +/- 1.7); 72% of the bulimic subjects meals were similar in size to the meals of the controls [167-4100 kJ (40-980 kcal)] but these meals were higher in carbohydrate and lower in fat in bulemic patients. Excessive caloric intake by bulimic subjects was because 28% of their meals were very large [range 4.427-28.150 MJ (1058-6728 kcal)]. Data gathered in a laboratory setting appears to be a reasonable replication of naturalistic feeding and suggest that such a laboratory may prove useful for future studies of feeding behaviors in humans.