The present study translated the major theories of obesity into physiological terms, then tested for the ways these theories might find physiological expression. Theoretical positions included the psychoanalytic perspective, emphasizing intrapsychic processes; psychosomatic perspective, emphasizing food as an anxiolytic agent; and Schachterian perspective, emphasizing heightened sensitivity to external stimuli. Additionally, two classificatory distinctions, age at onset of obesity and extent of dietary restraint, were examined. The later distinction suggested that Schachterian findings on obese behavior were due not to obesity, but to a dieting life style.