This study applied life history theory to eating behavior and examined the relationship between SES (Socio-Economic Status) and impulsiveness toward discounted food. Five hundred web-survey participants answered a questionnaire about impulsiveness toward discounted food, SES (childhood SES, current SES, food-specific poverty experience), cognition of discounted food (health effects, taste, attraction, limitations), and demographic factors (sex, age, household income). The result of hierarchical multiple regression analysis showed that childhood SES, food-specific poverty experience, attraction, limitations, and sex had an effect on impulsiveness toward discounted food. In addition, participants who experienced food-specific poverty had negative cognition regarding health effects, taste, and attraction, but nevertheless purchased discounted food impulsively. The necessity to verify the validity of the measurement of childhood SES and the effectiveness of intervening in negative beliefs were discussed.