According to emotional arousal theory (EAT), when emotionally aroused, obese people overeat and nonobese people do not. Lower socioeconomic-status urban obese and nonobese American Indians and White Americans were compared on a test of EAT. Subjects were administered the trait anxiety form of the State-Trait Anxiety Inventory Scale (S-TAIS) and then assigned to a high-anxiety (HA) or low-anxiety (LA) condition. They were then administered the state form of the S-TAIS and given a taste task to determine whether EAT is preditive of eating behaviors for both ethnic groups. Assessment results indicated that women were more trait and state anxious than were men; HA women, all HA subjects, HA American Indians, and nonobese American Indians were more state anxious than were corresponding groups. Behavioral indicator results generally supported EAT: All obese and high-anxiety-condition obese subjects consumed more food than did nonobese and low-anxiety-condition obese subjects, respectively. The overall consumption of food was greater with American Indians than with White Americans. This indicates that EAT does not fully explain American Indian eating behavior. An alternative stress-reaction theory is proposed to more fully account for American Indian eating behavior. Obese and nonobese American Indians overeat in response to stress. When stress occurs more frequently, intensely, and for longer duration, the potential for becoming obese increases (given food availability).